Support clearing all datatype cache

Merge pull request #4437 from umbraco/temp8-4302-bugfix-for-media-validation
Bugfixes for media validation
2019-02-08 11:40:49 +01:00 · 2019-02-08 09:50:26 +00:00 · 2019-02-08 09:56:24 +01:00 · 2019-02-08 09:02:27 +01:00 · 2019-02-08 16:12:30 +11:00 · 2019-02-08 16:08:29 +11:00
2728 changed files with 69675 additions and 92069 deletions
@@ -33,4 +33,8 @@ dotnet_naming_style.prefix_underscore.required_prefix = _
 [*.cs]
 csharp_style_var_for_built_in_types = true:suggestion
 csharp_style_var_when_type_is_apparent = true:suggestion
-csharp_style_var_elsewhere = true:suggestion
+csharp_style_var_elsewhere = true:suggestion
+csharp_prefer_braces = false : none
+
+[*.{js,less}]
+trim_trailing_whitespace = false
@@ -1,4 +1,4 @@
-_Looking for Umbraco version 8? [Click here](https://github.com/umbraco/Umbraco-CMS/blob/temp8/docs/CONTRIBUTING.md) to go to the v8 branch_
+_Looking for Umbraco version 8? [Click here](https://github.com/umbraco/Umbraco-CMS/blob/temp8/.github/V8_GETTING_STARTED.md) to go to the v8 branch_
 # Contributing to Umbraco CMS

 👍🎉 First off, thanks for taking the time to contribute! 🎉👍
@@ -16,9 +16,9 @@ This document gives you a quick overview on how to get started, we will link to

 ## Guidelines for contributions we welcome

-Not all changes are wanted so on occassion we might close a PR without merging it. We will give you feedback why we can't accept your changes and we'll be nice about it, thanking you for spending your valueable time.
+Not all changes are wanted, so on occassion we might close a PR without merging it. We will give you feedback why we can't accept your changes and we'll be nice about it, thanking you for spending your valuable time.

-We have [documented what we consider small and large changes](CONTRIBUTION_GUIDELINES.md), make sure to talk to us before making large changes.
+We have [documented what we consider small and large changes](CONTRIBUTION_GUIDELINES.md). Make sure to talk to us before making large changes.

 Remember, if an issue is in the `Up for grabs` list or you've asked for some feedback before you sent us a PR, your PR will not be closed as unwanted.

@@ -36,7 +36,7 @@ Great question! The short version goes like this:

  * **Build** - build your fork of Umbraco locally as described in [building Umbraco from source code](BUILD.md)
  * **Change** - make your changes, experiment, have fun, explore and learn, and don't be afraid. We welcome all contributions and will [happily give feedback](#questions)
-  * **Commit** - done? Yay! 🎉 It is recommended to create a new branch now and name it after the issue you're fixing, we usually follow the format: `temp-U4-12345`. This means it's a temporary branch for the particular issue you're working on, in this case `U4-12345`
+  * **Commit** - done? Yay! 🎉 It is recommended to create a new branch now and name it after the issue you're fixing, we usually follow the format: `temp-12345`. This means it's a temporary branch for the particular issue you're working on, in this case `12345`
  * **Push** - great, now you can push the changes up to your fork on GitHub
  * **Create pull request** - exciting! You're ready to show us your changes (or not quite ready, you just need some feedback to progress). GitHub has picked up on the new branch you've pushed and will offer to create a Pull Request. Click that green button and away you go.

@@ -72,7 +72,6 @@ The pull request team consists of a member of Umbraco HQ, [Sebastiaan](https://g
 - [Anders Bjerner](https://github.com/abjerner)
 - [Dave Woestenborghs](https://github.com/dawoe)
 - [Emma Burstow](https://github.com/emmaburstow)
- [Kyle Weems](https://github.com/cssquirrel)
 - [Poornima Nayar](https://github.com/poornimanayar)

 These wonderful volunteers will provide you with a first reply to your PR, review and test out your changes and might ask more questions. After that they'll let Umbraco HQ know if everything seems okay. 
@@ -83,7 +82,6 @@ You can get in touch with [the PR team](#the-pr-team) in multiple ways, we love

 - If there's an existing issue on the issue tracker then that's a good place to leave questions and discuss how to start or move forward
 - Unsure where to start? Did something not work as expected? Try leaving a note in the ["Contributing to Umbraco"](https://our.umbraco.com/forum/contributing-to-umbraco-cms/) forum, the team monitors that one closely
- We're also [active in the Gitter chatroom](https://gitter.im/umbraco/Umbraco-CMS)

 ## Code of Conduct

@@ -19,13 +19,13 @@ When contributing code to Umbraco there's plenty of things you'll want to know,
  * [What branch should I target for my contributions?](#what-branch-should-i-target-for-my-contributions)
  * [Building Umbraco from source code](#building-umbraco-from-source-code)
  * [Keeping your Umbraco fork in sync with the main repository](#keeping-your-umbraco-fork-in-sync-with-the-main-repository)
-  
+
 ## How Can I Contribute?

 ### Reporting Bugs
 This section guides you through submitting a bug report for Umbraco CMS. Following these guidelines helps maintainers and the community understand your report 📝, reproduce the behavior 💻 💻, and find related reports 🔎.

-Before creating bug reports, please check [this list](#before-submitting-a-bug-report) as you might find out that you don't need to create one. When you are creating a bug report, please [include as many details as possible](#how-do-i-submit-a-good-bug-report). Fill out [the required template](http://issues.umbraco.org/issues#newissue=61-30118), the information it asks for helps us resolve issues faster.
+Before creating bug reports, please check [this list](#before-submitting-a-bug-report) as you might find out that you don't need to create one. When you are creating a bug report, please [include as many details as possible](#how-do-i-submit-a-good-bug-report). Fill out [the required template](https://github.com/umbraco/Umbraco-CMS/issues/new/choose), the information it asks for helps us resolve issues faster.

 > **Note:** If you find a **Closed** issue that seems like it is the same thing that you're experiencing, open a new issue and include a link to the original issue in the body of your new one.

@@ -52,7 +52,7 @@ Provide more context by answering these questions:

 Include details about your configuration and environment:

-  * **Which version of Umbraco are you using?** 
+  * **Which version of Umbraco are you using?**
  * **What is the environment you're using Umbraco in?** Is this a problem on your local machine or on a server. Tell us about your configuration: Windows version, IIS/IISExpress, database type, etc.
  * **Which packages do you have installed?**

@@ -80,7 +80,7 @@ The most successful pull requests usually look a like this:
  * Unit tests, while optional are awesome, thank you!
  * New code is commented with documentation from which [the reference documentation](https://our.umbraco.com/documentation/Reference/) is generated

-Again, these are guidelines, not strict requirements. 
+Again, these are guidelines, not strict requirements.

 ## Making changes after the PR was opened

@@ -90,7 +90,7 @@ If you make the corrections we ask for in the same branch and push them to your

 To be honest, we don't like rules very much. We trust you have the best of intentions and we encourage you to create working code. If it doesn't look perfect then we'll happily help clean it up.

-That said, the Umbraco development team likes to follow the hints that ReSharper gives us (no problem if you don't have this installed) and we've added a `.editorconfig` file so that Visual Studio knows what to do with whitespace, line endings, etc. 
+That said, the Umbraco development team likes to follow the hints that ReSharper gives us (no problem if you don't have this installed) and we've added a `.editorconfig` file so that Visual Studio knows what to do with whitespace, line endings, etc.

 ## What should I know before I get started?

@@ -104,7 +104,6 @@ There's two big areas that you should know about:
  You may need to run the following commands to set up gulp properly:
  ```
  npm cache clean
-  npm install -g bower
  npm install -g gulp
  npm install -g gulp-cli
  npm install
@@ -125,6 +124,12 @@ We like to use [Gitflow as much as possible](https://jeffkreeftmeijer.com/git-fl

 ### Building Umbraco from source code

+In order to build the Umbraco source code locally, first make sure you have the following installed.
+
+  * Visual Studio 2017 v15.3+
+  * Node v10+ (Installed via `build.bat` script. If you already have it installed, make sure you're running at least v10)
+  * npm v6.4.1+ (Installed via `build.bat` script. If you already have it installed, make sure you're running at least v6.4.1)
+
 The easiest way to get started is to run `build.bat` which will build both the backoffice (also known as "Belle") and the Umbraco core. You can then easily start debugging from Visual Studio, or if you need to debug Belle you can run `gulp dev` in `src\Umbraco.Web.UI.Client`. See [this page](BUILD.md) for more details.

 Alternatively, you can open `src\umbraco.sln` in Visual Studio 2017 (version 15.3 or higher, [the community edition is free](https://www.visualstudio.com/thank-you-downloading-visual-studio/?sku=Community&rel=15) for you to use to contribute to Open Source projects). In Visual Studio, find the Task Runner Explorer (in the View menu under Other Windows) and run the build task under the gulpfile.
@@ -13,7 +13,7 @@ We’re usually able to handle small PRs pretty quickly. A community volunteer w

 Umbraco HQ will regularly mark newly created issues on the issue tracker with the `Up for grabs` tag. This means that the proposed changes are wanted in Umbraco but the HQ does not have the time to make them at this time. These issues are usually small enough to fit in the "Small PRs" category and we encourage anyone to pick them up and help out.  

-If you do start working on something, make sure leave a small comment on the issue saying something like: "I'm working on this". That way other people stumbling upon the issue know they don't need to pick it up, someone already has.
+If you do start working on something, make sure to leave a small comment on the issue saying something like: "I'm working on this". That way other people stumbling upon the issue know they don't need to pick it up, someone already has.

 ## Large PRs
 New features and large refactorings - can be recognized by seeing a large number of changes, plenty of new files, updates to package manager files (NuGet’s packages.config, NPM’s packages.json, etc.).  
@@ -30,4 +30,4 @@ If a larger pull request is encouraged by Umbraco HQ, the process will be simila

 If it doesn’t fit in CMS right now, we will likely encourage you to make it into a package instead. A package is a great way to check out popularity of a feature, learn how people use it, validate good usability and to fix bugs.  

-Eventually, a package could "graduate" to be included in the CMS.  
+Eventually, a package could "graduate" to be included in the CMS.  
@@ -1,11 +1,12 @@
 ### Prerequisites

- [ ] I have [created an issue](https://github.com/umbraco/Umbraco-CMS/issues) for the proposed changes in this PR, the link is:
 - [ ] I have added steps to test this contribution in the description below

+If there's an existing issue for this PR then this fixes: <!-- link to the issue here! -->
+
 ### Description
-<!-- A description of the changes proposed in the pull-request -->
-<!-- Make sure to link to the related issue number so we can easily find it in the issue tracker -->
+<!-- A description of the changes proposed in the pull-request and how to test these changes -->
+


 <!-- Thanks for contributing to Umbraco CMS! -->
@@ -1,4 +1,5 @@
 _You are browsing the Umbraco v8 branch. Umbraco 8 is currently under development._
+[![pullreminders](https://pullreminders.com/badge.svg)](https://pullreminders.com?ref=badge)

 _Looking for Umbraco version 7? [Click here](https://github.com/umbraco/Umbraco-CMS) to go to the v7 branch._

@@ -6,7 +7,7 @@ _Ready to try out Version 8? [See the quick start guide](V8_GETTING_STARTED.md).

 When is Umbraco 8 coming?
 =========================
-When it's ready. We're done with the major parts of the architecture work and are focusing on three seperate tracks to prepare Umbraco 8 for release:
+When it's ready. We're done with the major parts of the architecture work and are focusing on three separate tracks to prepare Umbraco 8 for release:
 1) Editor Track (_currently in progress_). Without editors, there's no market for Umbraco. So we want to make sure that Umbraco 8 is full of love for editors.
 2) Partner Track. Without anyone implementing Umbraco, there's nothing for editors to update. So we want to make sure that Umbraco 8 is a joy to implement
 3) Contributor Track. Without our fabulous ecosystem of both individual Umbracians and 3rd party ISVs, Umbraco wouldn't be as rich a platform as it is today. We want to make sure that it's easy, straight forward and as backwards-compatible as possible to create packages for Umbraco
@@ -15,7 +16,7 @@ Once a track is done, we start releasing previews where we ask people to test th

 Umbraco CMS
 ===========
-The friendliest, most flexible and fastest growing ASP.NET CMS used by more than 443,000 websites worldwide: [https://umbraco.com](https://umbraco.com)
+The friendliest, most flexible and fastest growing ASP.NET CMS, and used by more than 443,000 websites worldwide: [https://umbraco.com](https://umbraco.com)

 [![ScreenShot](img/vimeo.png)](https://vimeo.com/172382998/)

@@ -28,34 +29,34 @@ Umbraco is a free open source Content Management System built on the ASP.NET pla

 ## Umbraco - The Friendly CMS

-For the first time on the Microsoft platform, there is a free user and developer friendly CMS that makes it quick and easy to create websites - or a breeze to build complex web applications. Umbraco has award-winning integration capabilities and supports ASP.NET MVC or Web Forms, including User and Custom Controls, out of the box.
+For the first time on the Microsoft platform, there is a free user- and developer-friendly CMS that makes it quick and easy to create websites - and a breeze to build complex web applications. Umbraco has award-winning integration capabilities and supports ASP.NET MVC or Web Forms, including User and Custom Controls, right out of the box.

-Umbraco is not only loved by developers, but is a content editors dream. Enjoy intuitive editing tools, media management, responsive views and approval workflows to send your content live.
+Umbraco is not only loved by developers, but is a content editor's dream. Enjoy intuitive editing tools, media management, responsive views, and approval workflows to send your content live.

-Used by more than 443,000 active websites including Carlsberg, Segway, Amazon and Heinz and **The Official ASP.NET and IIS.NET website from Microsoft** ([https://asp.net](https://asp.net) / [https://iis.net](https://iis.net)), you can be sure that the technology is proven, stable and scales. Backed by the team at Umbraco HQ, and supported by a dedicated community of over 220,000 craftspeople globally, you can trust that Umbraco is a safe choice and is here to stay.
+Used by more than 443,000 active websites including Carlsberg, Segway, Amazon and Heinz and **The Official ASP.NET and IIS.NET website from Microsoft** ([https://asp.net](https://asp.net) / [https://iis.net](https://iis.net)), you can be sure that the technology is proven, stable and scalable. Backed by the team at Umbraco HQ, and supported by a dedicated community of over 220,000 craftspeople globally, you can trust that Umbraco is a safe choice and is here to stay.

 To view more examples, please visit [https://umbraco.com/case-studies-testimonials/](https://umbraco.com/case-studies-testimonials/)

 ## Why Open Source?
-As an Open Source platform, Umbraco is more than just a CMS. We are transparent with our roadmap for future versions, our incremental sprint planning notes are publicly accessible and community contributions and packages are available for all to use.
+As an Open Source platform, Umbraco is more than just a CMS. We are transparent with our roadmap for future versions, our incremental sprint planning notes are publicly accessible, and community contributions and packages are available for all to use.

 ## Trying out Umbraco CMS

-[Umbraco Cloud](https://umbraco.com/cloud) is the easiest and fastest way to use Umbraco yet with full support for all your custom .NET code and intergrations. You're up and running in less than a minute and your life will be made easier with automated upgrades and a built-in deployment engine. We offer a free 14 day trial, no credit card needed.
+[Umbraco Cloud](https://umbraco.com/cloud) is the easiest and fastest way to use Umbraco yet, with full support for all your custom .NET code and integrations. You're up and running in less than a minute, and your life will be made easier with automated upgrades and a built-in deployment engine. We offer a free 14-day trial, no credit card needed.

-If you want to DIY you can [download Umbraco](https://our.umbraco.com/download) either as a ZIP file or via NuGet. It's the same version of Umbraco CMS that powers Umbraco Cloud, but you'll need to find a place to host yourself and handling deployments and upgrades is all down to you.
+If you want to DIY, you can [download Umbraco](https://our.umbraco.com/download) either as a ZIP file or via NuGet. It's the same version of Umbraco CMS that powers Umbraco Cloud, but you'll need to find a place to host it yourself, and handling deployments and upgrades will be all up to you.

 ## Community

-Our friendly community is available 24/7 at the community hub we call ["Our Umbraco"](https://our.umbraco.com). Our Umbraco feature forums for questions and answers, documentation, downloadable plugins for Umbraco and a rich collection of community resources.
+Our friendly community is available 24/7 at the community hub we call ["Our Umbraco"](https://our.umbraco.com). Our Umbraco features forums for questions and answers, documentation, downloadable plugins for Umbraco, and a rich collection of community resources.

 ## Contribute to Umbraco

-Umbraco is contribution focused and community driven. If you want to contribute back to Umbraco please check out our [guide to contributing](CONTRIBUTING.md).
+Umbraco is contribution-focused and community-driven. If you want to contribute back to Umbraco, please check out our [guide to contributing](CONTRIBUTING.md).

 ## Found a bug?

 Another way you can contribute to Umbraco is by providing issue reports. For information on how to submit an issue report refer to our [online guide for reporting issues](CONTRIBUTING_DETAILED.md#reporting-bugs).

 You can comment and report issues on the [github issue tracker](https://github.com/umbraco/Umbraco-CMS/issues).
-Since [September 2018](https://umbraco.com/blog/a-second-take-on-umbraco-issue-tracker-hello-github-issues/) the old issue tracker is in read only mode, but can still be found at [http://issues.umbraco.org](http://issues.umbraco.org).
+Since [September 2018](https://umbraco.com/blog/a-second-take-on-umbraco-issue-tracker-hello-github-issues/), the old issue tracker is in read-only mode, but can still be found at [http://issues.umbraco.org](http://issues.umbraco.org).
@@ -11,7 +11,7 @@

 * Open the `/src/umbraco.sln` Visual Studio solution
 * Start the solution (easiest way is to use `ctrl + F5`)
-* When the solution is first built this may take some time since it will restore all nuget, npm and bower packages, build the .net solution and also build the angular solution
+* When the solution is first built this may take some time since it will restore all nuget and npm packages, build the .net solution and also build the angular solution
 * When the website starts you'll see the Umbraco installer and just follow the prompts
 * You're all set!

@@ -33,5 +33,5 @@ We recommend running the site with the Visual Studio since you'll be able to rem

 We are keeping track of [known issues and limitations here](http://issues.umbraco.org/issue/U4-11279). These line items will eventually be turned into actual tasks to be worked on. Feel free to help us keep this list updated if you find issues and even help fix some of these items. If there is a particular item you'd like to help fix please mention this on the task and we'll create a sub task for the item to continue discussion there.

-There's [a list of tasks for v8 that haven't been completed](https://issues.umbraco.org/issues?q=&project=U4&tagValue=&release=8.0.0&issueType=&resolvedState=open&search=search). If you are interested in helping out with any of these please mention this on the task. This list will be constantly updated as we begin to document and design some of the other tasks that still need to get done.
+There's [a list of tasks for v8 that haven't been completed](https://github.com/umbraco/Umbraco-CMS/labels/release%2F8.0.0). If you are interested in helping out with any of these please mention this on the task. This list will be constantly updated as we begin to document and design some of the other tasks that still need to get done.

@@ -13,6 +13,7 @@
 *.suo
 *.vs10x
 *.ndproj
+*.ignorer.*

 # common directories
 .DS_Store
@@ -107,6 +108,7 @@ src/Umbraco.Web.UI.Client/[Bb]uild/[Bb]elle/
 src/Umbraco.Web.UI/[Uu]ser[Cc]ontrols/

 src/Umbraco.Web.UI.Client/src/[Ll]ess/*.css
+src/Umbraco.Web.UI.Client/vwd.webinfo

 src/Umbraco.Web.UI/App_Plugins/*
 src/*.psess
@@ -155,4 +157,4 @@ build/temp/



-# eof
+# eof
@@ -3,57 +3,57 @@
 [string]$Directory
 )
 $workingDirectory = $Directory
-CD $workingDirectory
+CD "$($workingDirectory)"

 # Clone repo
-$fullGitUrl = "https://$env:GIT_URL/$env:GIT_REPOSITORYNAME.git"
-git clone $fullGitUrl 2>&1 | % { $_.ToString() } 
+$fullGitUrl = "https://$($env:GIT_URL)/$($env:GIT_REPOSITORYNAME).git"
+git clone $($fullGitUrl) $($env:GIT_REPOSITORYNAME) 2>&1 | % { $_.ToString() } 

 # Remove everything so that unzipping the release later will update everything
 # Don't remove the readme file nor the git directory
 Write-Host "Cleaning up git directory before adding new version"
-Remove-Item -Recurse $workingDirectory\$env:GIT_REPOSITORYNAME\* -Exclude README.md,.git
+Remove-Item -Recurse "$($workingDirectory)\$($env:GIT_REPOSITORYNAME)\*" -Exclude README.md,.git

 # Find release zip
-$zipsDir = "$workingDirectory\$env:BUILD_DEFINITIONNAME\zips"
+$zipsDir = "$($workingDirectory)\$($env:BUILD_DEFINITIONNAME)\zips"
 $pattern = "UmbracoCms.([0-9]{1,2}.[0-9]{1,3}.[0-9]{1,3}).zip"
-Write-Host "Searching for Umbraco release files in $workingDirectory\$zipsDir for a file with pattern $pattern"
-$file = (Get-ChildItem $zipsDir | Where-Object { $_.Name -match "$pattern" })
+Write-Host "Searching for Umbraco release files in $($zipsDir) for a file with pattern $($pattern)"
+$file = (Get-ChildItem "$($zipsDir)" | Where-Object { $_.Name -match "$($pattern)" })

 if($file)
 {
    # Get release name
-    $version = [regex]::Match($file.Name, $pattern).captures.groups[1].value
-    $releaseName = "Umbraco $version"
-    Write-Host "Found $releaseName"
+    $version = [regex]::Match($($file.Name), $($pattern)).captures.groups[1].value
+    $releaseName = "Umbraco $($version)"
+    Write-Host "Found $($releaseName)"
    
    # Unzip into repository to update release
    Add-Type -AssemblyName System.IO.Compression.FileSystem
-    Write-Host "Unzipping $($file.FullName) to $workingDirectory\$env:GIT_REPOSITORYNAME"
-    [System.IO.Compression.ZipFile]::ExtractToDirectory("$($file.FullName)", "$workingDirectory\$env:GIT_REPOSITORYNAME")
+    Write-Host "Unzipping $($file.FullName) to $($workingDirectory)\$($env:GIT_REPOSITORYNAME)"
+    [System.IO.Compression.ZipFile]::ExtractToDirectory("$($file.FullName)", "$($workingDirectory)\$($env:GIT_REPOSITORYNAME)")
    
    # Telling git who we are
    git config --global user.email "coffee@umbraco.com" 2>&1 | % { $_.ToString() }
    git config --global user.name "Umbraco HQ" 2>&1 | % { $_.ToString() }
    
    # Commit
-    CD $env:GIT_REPOSITORYNAME
-    Write-Host "Committing Umbraco $version Release from Build Output"
+    CD "$($workingDirectory)\$($env:GIT_REPOSITORYNAME)"
+    Write-Host "Committing Umbraco $($version) Release from Build Output"

    git add . 2>&1 | % { $_.ToString() } 
-    git commit -m " Release $releaseName from Build Output" 2>&1 | % { $_.ToString() } 
+    git commit -m " Release $($releaseName) from Build Output" 2>&1 | % { $_.ToString() } 

    # Tag the release
-    git tag -a "v$version" -m "v$version"
+    git tag -a "v$($version)" -m "v$($version)"

    # Push release to master
-    $fullGitAuthUrl = "https://$($env:GIT_USERNAME):$GitHubPersonalAccessToken@$env:GIT_URL/$env:GIT_REPOSITORYNAME.git"
-    git push $fullGitAuthUrl 2>&1 | % { $_.ToString() } 
+    $fullGitAuthUrl = "https://$($env:GIT_USERNAME):$($GitHubPersonalAccessToken)@$($env:GIT_URL)/$($env:GIT_REPOSITORYNAME).git"
+    git push $($fullGitAuthUrl) 2>&1 | % { $_.ToString() } 

    #Push tag to master
-    git push $fullGitAuthUrl --tags 2>&1 | % { $_.ToString() }
+    git push $($fullGitAuthUrl) --tags 2>&1 | % { $_.ToString() }
 }
 else
 {
-    Write-Error "Umbraco release file not found, searched in $workingDirectory\$zipsDir for a file with pattern $pattern - cancelling"
+    Write-Error "Umbraco release file not found, searched in $($workingDirectory)\$($zipsDir) for a file with pattern $($pattern) - canceling"
 }
@@ -8,38 +8,42 @@
        <owners>Umbraco HQ</owners>
        <licenseUrl>http://opensource.org/licenses/MIT</licenseUrl>
        <projectUrl>http://umbraco.com/</projectUrl>
-        <iconUrl>http://umbraco.com/media/357769/100px_transparent.png</iconUrl>
+        <iconUrl>https://umbraco.com/dist/nuget/logo-small.png</iconUrl>
        <requireLicenseAcceptance>false</requireLicenseAcceptance>
        <description>Contains the core assemblies needed to run Umbraco Cms. This package only contains assemblies and can be used for package development. Use the UmbracoCms package to setup Umbraco in Visual Studio as an ASP.NET project.</description>
        <summary>Contains the core assemblies needed to run Umbraco Cms</summary>
        <language>en-US</language>
        <tags>umbraco</tags>
        <dependencies>
-            <!--
-              note: dependencies are specified as [x.y.z,x.999999) eg [2.1.0,2.999999) and NOT [2.1.0,3.0.0) because
-              the latter would pick anything below 3.0.0 and that includes prereleases such as 3.0.0-alpha, and we do
-              not want this to happen as the alpha of the next major is, really, the next major already.
-            -->
-            <dependency id="AutoMapper" version="[7.0.1,7.999999)" />
-            <dependency id="LightInject" version="[5.1.2,5.999999)" />
-            <dependency id="LightInject.Annotation" version="[1.1.0,1.999999)" />
-            <dependency id="LightInject.Web" version="[2.0.0,2.999999)" />
-            <dependency id="Microsoft.AspNet.Identity.Core" version="[2.2.2,2.999999)" />
-            <dependency id="Microsoft.AspNet.WebApi.Client" version="[5.2.6,5.999999)" />
-            <dependency id="Microsoft.Owin" version="[4.0.0,4.999999)" />
-            <dependency id="MiniProfiler" version="[3.2.0.157,3.999999)" />
-            <dependency id="MySql.Data" version="[6.10.7,6.999999)" />
-            <dependency id="Newtonsoft.Json" version="[11.0.2,11.999999)" />
-            <dependency id="Semver" version="[2.0.4,2.999999)" />
-            <dependency id="Serilog" version="[2.7.1,2.999999)" />
-            <dependency id="Serilog.Enrichers.Process" version="[2.0.1,2.999999)" />
-            <dependency id="Serilog.Enrichers.Thread" version="[3.0.0,3.999999)" />
-            <dependency id="Serilog.Filters.Expressions" version="[2.0.0,2.999999)" />
-            <dependency id="Serilog.Formatting.Compact" version="[1.0.0,1.999999)" />
-            <dependency id="Serilog.Settings.AppSettings" version="[2.1.2,2.999999)" />
-            <dependency id="Serilog.Sinks.File" version="[4.0.0,4.999999)" />
-            <dependency id="Umbraco.SqlServerCE" version="[4.0.0.1,4.999999)" />
-            <dependency id="NPoco" version="[3.9.4,3.999999)" />
+
+            <group targetFramework="net472">
+                <!--
+                  note: dependencies are specified as [x.y.z,x.999999) eg [2.1.0,2.999999) and NOT [2.1.0,3.0.0) because
+                  the latter would pick anything below 3.0.0 and that includes prereleases such as 3.0.0-alpha, and we do
+                  not want this to happen as the alpha of the next major is, really, the next major already.
+                -->
+                <dependency id="AutoMapper" version="[8.0.0,8.999999)" />
+                <dependency id="LightInject" version="[5.4.0,5.999999)" />
+                <dependency id="LightInject.Annotation" version="[1.1.0,1.999999)" />
+                <dependency id="LightInject.Web" version="[2.0.0,2.999999)" />
+                <dependency id="Microsoft.AspNet.Identity.Core" version="[2.2.2,2.999999)" />
+                <dependency id="Microsoft.AspNet.WebApi.Client" version="[5.2.7,5.999999)" />
+                <dependency id="Microsoft.Owin" version="[4.0.1,4.999999)" />
+                <dependency id="MiniProfiler" version="[4.0.138,4.999999)" />
+                <dependency id="Newtonsoft.Json" version="[12.0.1,12.999999)" />
+                <dependency id="Semver" version="[2.0.4,2.999999)" />
+                <dependency id="Serilog" version="[2.8.0,2.999999)" />
+                <dependency id="Serilog.Enrichers.Process" version="[2.0.1,2.999999)" />
+                <dependency id="Serilog.Enrichers.Thread" version="[3.0.0,3.999999)" />
+                <dependency id="Serilog.Filters.Expressions" version="[2.0.0,2.999999)" />
+                <dependency id="Serilog.Formatting.Compact" version="[1.0.0,1.999999)" />
+                <dependency id="Serilog.Formatting.Compact.Reader" version="[1.0.3,1.999999)" />
+                <dependency id="Serilog.Settings.AppSettings" version="[2.2.2,2.999999)" />
+                <dependency id="Serilog.Sinks.File" version="[4.0.0,4.999999)" />
+                <dependency id="Umbraco.SqlServerCE" version="[4.0.0.1,4.999999)" />
+                <dependency id="NPoco" version="[3.9.4,3.999999)" />
+            </group>
+            
        </dependencies>
    </metadata>
    <files>
@@ -8,38 +8,42 @@
        <owners>Umbraco HQ</owners>
        <licenseUrl>http://opensource.org/licenses/MIT</licenseUrl>
        <projectUrl>http://umbraco.com/</projectUrl>
-        <iconUrl>http://umbraco.com/media/357769/100px_transparent.png</iconUrl>
+        <iconUrl>https://umbraco.com/dist/nuget/logo-small.png</iconUrl>
        <requireLicenseAcceptance>false</requireLicenseAcceptance>
        <description>Contains the web assemblies needed to run Umbraco Cms. This package only contains assemblies and can be used for package development. Use the UmbracoCms package to setup Umbraco in Visual Studio as an ASP.NET project.</description>
        <summary>Contains the core assemblies needed to run Umbraco Cms</summary>
        <language>en-US</language>
        <tags>umbraco</tags>
        <dependencies>
-            <!--
-              note: dependencies are specified as [x.y.z,x.999999) eg [2.1.0,2.999999) and NOT [2.1.0,3.0.0) because
-              the latter would pick anything below 3.0.0 and that includes prereleases such as 3.0.0-alpha, and we do
-              not want this to happen as the alpha of the next major is, really, the next major already.
-            -->
-            <dependency id="UmbracoCms.Core" version="[$version$]" />
-            <dependency id="AutoMapper" version="[7.0.1,7.999999)" />
-            <dependency id="ClientDependency" version="[1.9.7,1.999999)" />
-            <dependency id="ClientDependency-Mvc5" version="[1.8.0,1.999999)" />
-            <dependency id="CSharpTest.Net.Collections" version="[14.906.1403.1082,14.999999)" />
-            <dependency id="Examine" version="[1.0.0-beta025,1.999999)" />
-            <dependency id="Lucene.Net.Contrib" version="[3.0.3,3.999999)" />
-            <dependency id="HtmlAgilityPack" version="[1.8.9,1.999999)" />
-            <dependency id="ImageProcessor" version="[2.6.2.25,2.999999)" />
-            <dependency id="LightInject.Mvc" version="[2.0.0,2.999999)" />
-            <dependency id="LightInject.WebApi" version="[2.0.0,2.999999)" />
-            <dependency id="Markdown" version="[2.2.1,2.999999)" />
-            <dependency id="Microsoft.AspNet.Identity.Owin" version="[2.2.2,2.999999)" />
-            <dependency id="Microsoft.AspNet.Mvc" version="[5.2.6,5.999999)" />
-            <dependency id="Microsoft.AspNet.SignalR.Core" version="[2.2.3,2.999999)" />
-            <dependency id="Microsoft.AspNet.WebApi" version="[5.2.6,5.999999)" />
-            <dependency id="Microsoft.Owin.Host.SystemWeb" version="[4.0.0,4.999999)" />
-            <dependency id="Microsoft.Owin.Security.Cookies" version="[4.0.0,4.999999)" />
-            <dependency id="Microsoft.Owin.Security.OAuth" version="[4.0.0,4.999999)" />
-            <dependency id="System.Threading.Tasks.Dataflow" version="[4.8.0,4.999999)" />
+
+            <group targetFramework="net472">
+
+                <!--
+                  note: dependencies are specified as [x.y.z,x.999999) eg [2.1.0,2.999999) and NOT [2.1.0,3.0.0) because
+                  the latter would pick anything below 3.0.0 and that includes prereleases such as 3.0.0-alpha, and we do
+                  not want this to happen as the alpha of the next major is, really, the next major already.
+                -->
+                <dependency id="UmbracoCms.Core" version="[$version$]" />
+                <dependency id="ClientDependency" version="[1.9.7,1.999999)" />
+                <dependency id="ClientDependency-Mvc5" version="[1.8.0,1.999999)" />
+                <dependency id="CSharpTest.Net.Collections" version="[14.906.1403.1082,14.999999)" />
+                <dependency id="Examine" version="[1.0.0-beta078,1.999999)" />
+                <dependency id="HtmlAgilityPack" version="[1.8.14,1.999999)" />
+                <dependency id="ImageProcessor" version="[2.6.2.25,2.999999)" />
+                <dependency id="LightInject.Mvc" version="[2.0.0,2.999999)" />
+                <dependency id="LightInject.WebApi" version="[2.0.0,2.999999)" />
+                <dependency id="Markdown" version="[2.2.1,2.999999)" />
+                <dependency id="Microsoft.AspNet.Identity.Owin" version="[2.2.2,2.999999)" />
+                <dependency id="Microsoft.AspNet.Mvc" version="[5.2.7,5.999999)" />
+                <dependency id="Microsoft.AspNet.SignalR.Core" version="[2.4.0,2.999999)" />
+                <dependency id="Microsoft.AspNet.WebApi" version="[5.2.7,5.999999)" />
+                <dependency id="Microsoft.Owin.Host.SystemWeb" version="[4.0.1,4.999999)" />
+                <dependency id="Microsoft.Owin.Security.Cookies" version="[4.0.1,4.999999)" />
+                <dependency id="Microsoft.Owin.Security.OAuth" version="[4.0.1,4.999999)" />
+                <dependency id="System.Threading.Tasks.Dataflow" version="[4.9.0,4.999999)" />
+
+            </group>
+            
        </dependencies>
    </metadata>
    <files>
@@ -8,32 +8,38 @@
        <owners>Umbraco HQ</owners>
        <licenseUrl>http://opensource.org/licenses/MIT</licenseUrl>
        <projectUrl>http://umbraco.com/</projectUrl>
-        <iconUrl>http://umbraco.com/media/357769/100px_transparent.png</iconUrl>
+        <iconUrl>https://umbraco.com/dist/nuget/logo-small.png</iconUrl>
        <requireLicenseAcceptance>false</requireLicenseAcceptance>
        <description>Installs Umbraco Cms in your Visual Studio ASP.NET project</description>
        <summary>Installs Umbraco Cms in your Visual Studio ASP.NET project</summary>
        <language>en-US</language>
        <tags>umbraco</tags>
        <dependencies>
-            <dependency id="UmbracoCms.Web" version="[$version$]" />
-            <!--
-              note: dependencies are specified as [x.y.z,x.999999) eg [2.1.0,2.999999) and NOT [2.1.0,3.0.0) because
-              the latter would pick anything below 3.0.0 and that includes prereleases such as 3.0.0-alpha, and we do
-              not want this to happen as the alpha of the next major is, really, the next major already.
-            -->
-            <dependency id="Microsoft.AspNet.SignalR.Core" version="[2.2.3, 2.999999)" />
-            <dependency id="Umbraco.ModelsBuilder.Ui" version="[8.0.0-alpha.24]" />
-            <dependency id="ImageProcessor.Web" version="[4.9.3.25,4.999999)" />
-            <dependency id="ImageProcessor.Web.Config" version="[2.4.1.19,2.999999)" />
-            <dependency id="Microsoft.CodeDom.Providers.DotNetCompilerPlatform" version="[2.0.0,2.999999)" />
-            <dependency id="Microsoft.Net.Compilers" version="[2.9.0,2.999999)" />
+
+            <group targetFramework="net472">
+
+                <dependency id="UmbracoCms.Web" version="[$version$]" />
+                <!--
+                  note: dependencies are specified as [x.y.z,x.999999) eg [2.1.0,2.999999) and NOT [2.1.0,3.0.0) because
+                  the latter would pick anything below 3.0.0 and that includes prereleases such as 3.0.0-alpha, and we do
+                  not want this to happen as the alpha of the next major is, really, the next major already.
+                -->
+                <dependency id="Microsoft.AspNet.SignalR.Core" version="[2.4.0, 2.999999)" />
+                <dependency id="Umbraco.ModelsBuilder.Ui" version="[8.0.0-alpha.37]" />
+                <dependency id="ImageProcessor.Web" version="[4.9.3.25,4.999999)" />
+                <dependency id="ImageProcessor.Web.Config" version="[2.4.1.19,2.999999)" />
+                <dependency id="Microsoft.CodeDom.Providers.DotNetCompilerPlatform" version="[2.0.1,2.999999)" />
+                <dependency id="Microsoft.Net.Compilers" version="[2.10.0,2.999999)" />
+
+            </group>
+
+            
        </dependencies>
    </metadata>
    <files>
        <!-- files -->
        <file src="$BuildTmp$\Configs\**" target="Content\Config" exclude="$BuildTmp$\Configs\Web.config.transform" />
        <file src="$BuildTmp$\WebApp\Views\**" target="Content\Views" exclude="$BuildTmp$\WebApp\Views\Web.config" />
-        <file src="$BuildTmp$\WebApp\default.aspx" target="Content\default.aspx" />
        <file src="$BuildTmp$\WebApp\Global.asax" target="Content\Global.asax" />
        <file src="$BuildTmp$\WebApp\config\BackOfficeTours\**" target="Content\Config\BackOfficeTours" />
        <file src="$BuildTmp$\WebApp\Media\Web.config" target="Content\Media\Web.config" />
@@ -52,12 +58,9 @@
        <!-- config transforms -->
        <!-- beware! config transforms not supported by PackageReference -->
        <file src="tools\Web.config.install.xdt" target="Content\Web.config.install.xdt" />
-        <file src="tools\applications.config.install.xdt" target="Content\config\applications.config.install.xdt" />
        <file src="tools\ClientDependency.config.install.xdt" target="Content\config\ClientDependency.config.install.xdt" />
-        <file src="tools\Dashboard.config.install.xdt" target="Content\config\Dashboard.config.install.xdt" />
-        <file src="tools\trees.config.install.xdt" target="Content\config\trees.config.install.xdt" />
        <file src="tools\umbracoSettings.config.install.xdt" target="Content\config\umbracoSettings.config.install.xdt" />
-        <file src="tools\Views.Web.config.install.xdt" target="Views\Web.config.install.xdt" /> <!-- FIXME Content\ !! and then... transform?! -->
+        <file src="tools\Views.Web.config.install.xdt" target="Views\Web.config.install.xdt" /> <!-- FIXME: Content\ !! and then... transform?! -->

        <!-- UmbracoCms props and targets -->
        <file src="build\**" target="build" />
@@ -1,95 +0,0 @@
-<?xml version="1.0"?>
-<dashBoard xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
-  <section alias="StartupSettingsDashboardSection" xdt:Locator="Match(alias)" xdt:Transform="InsertIfMissing">
-    <tab caption="Get Started" xdt:Locator="Match(caption)" xdt:Transform="Remove" />
-    <tab caption="Welcome"  xdt:Locator="Match(caption)" xdt:Transform="InsertIfMissing">
-      <control showOnce="true" addPanel="true" panelCaption="" xdt:Transform="InsertIfMissing">
-        views/dashboard/settings/settingsdashboardintro.html
-      </control>
-    </tab>
-  </section>
-
-  <section alias="StartupFormsDashboardSection" xdt:Locator="Match(alias)" xdt:Transform="InsertIfMissing">
-    <areas>
-      <area>forms</area>
-    </areas>
-    <tab caption="Install Umbraco Forms">
-      <control showOnce="true" addPanel="true" panelCaption="">
-        views/dashboard/forms/formsdashboardintro.html
-      </control>
-    </tab>
-  </section>
-
-  <section alias="StartupDeveloperDashboardSection" xdt:Locator="Match(alias)" xdt:Transform="InsertIfMissing">
-    <areas xdt:Transform="InsertIfMissing">
-      <area xdt:Transform="InsertIfMissing">developer</area>
-    </areas>  
-  </section>
-  
-  <section alias="StartupDeveloperDashboardSection">
-    <tab caption="Get Started" xdt:Locator="Match(caption)" xdt:Transform="Replace">
-      <control showOnce="true" addPanel="true" panelCaption="">
-        views/dashboard/developer/developerdashboardvideos.html
-      </control>
-    </tab>
-    <tab caption="Examine Management" xdt:Locator="Match(caption)" xdt:Transform="Remove" />
-  </section>
-  
-  <section alias="StartupDeveloperDashboardSection" xdt:Locator="Match(alias)" xdt:Transform="InsertIfMissing">
-	<tab caption="Examine Management" xdt:Locator="Match(caption)" xdt:Transform="InsertIfMissing">
-      <control>
-        views/dashboard/developer/examinemanagement.html
-      </control>
-    </tab>
-  </section>
-  
-  <section alias="StartupMediaDashboardSection" xdt:Locator="Match(alias)" xdt:Transform="InsertIfMissing">
-    <tab caption="Get Started" xdt:Locator="Match(caption)" xdt:Transform="Remove" />
-    <tab caption="Content"  xdt:Locator="Match(caption)" xdt:Transform="InsertIfMissing" />
-    <tab caption="Content"  xdt:Locator="Match(caption)" xdt:Transform="Replace">
-      <control showOnce="false" addPanel="false" panelCaption="">
-        views/dashboard/media/mediafolderbrowser.html
-      </control>
-    </tab>
-  </section>
-  
-  <section alias="StartupMemberDashboardSection" xdt:Locator="Match(alias)" xdt:Transform="InsertIfMissing">
-    <tab caption="Get Started" xdt:Locator="Match(caption)" xdt:Transform="Remove" />
-    <tab caption="Get Started" xdt:Transform="Insert">
-      <control showOnce="true" addPanel="true" panelCaption="">
-        views/dashboard/members/membersdashboardvideos.html
-      </control>
-    </tab>
-  </section>
-  
-  <section alias="uGoLiveDashboardSection" xdt:Locator="Match(alias)" xdt:Transform="Remove" />
-  
-  <section alias="ExamineManagement" xdt:Locator="Match(alias)" xdt:Transform="Remove" />
-    
-  <section alias="StartupDashboardSection">
-	<tab caption="Change Password" xdt:Locator="Match(caption)" xdt:Transform="Remove" />
-	<tab caption="Last Edits" xdt:Locator="Match(caption)" xdt:Transform="Remove" />
-  </section>
-
-  <section alias="RedirectUrlManagement" xdt:Locator="Match(alias)" xdt:Transform="InsertIfMissing">
-    <areas>
-      <area>content</area>
-    </areas>
-    <tab caption="Redirect URL Management">
-      <control>
-        views/dashboard/developer/redirecturls.html
-      </control>
-    </tab>
-  </section>
-
-  <section alias="UmbracoHealthCheck" xdt:Locator="Match(alias)" xdt:Transform="InsertIfMissing">
-    <areas>
-      <area>developer</area>
-    </areas>
-    <tab caption="Health Check">
-      <control>
-        views/dashboard/developer/healthcheck.html
-      </control>
-    </tab>
-  </section>
-</dashBoard>
@@ -2,17 +2,11 @@
 <configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
  <configSections xdt:Transform="InsertIfMissing" />
  <configSections>
-    <section name="FileSystemProviders" xdt:Locator="Match(name)" xdt:Transform="Remove" />
-    <section name="ExamineLuceneIndexSets" type="Umbraco.Examine.Config.IndexSets, Umbraco.Examine" requirePermission="false" xdt:Locator="Match(name)" xdt:Transform="SetAttributes(type,requirePermission)" />
-
-    <sectionGroup name="applicationSettings" xdt:Locator="Match(name)">
-      <section name="umbraco.presentation.Properties.Settings" xdt:Locator="Match(name)" xdt:Transform="Remove" />
-    </sectionGroup>
+    <sectionGroup name="applicationSettings" xdt:Locator="Match(name)" xdt:Transform="Remove" />
    <sectionGroup name="system.web.webPages.razor" xdt:Locator="Match(name)" xdt:Transform="Remove" />
    <sectionGroup name="umbracoConfiguration" xdt:Locator="Match(name)" xdt:Transform="InsertIfMissing">
      <section name="settings" type="Umbraco.Core.Configuration.UmbracoSettings.UmbracoSettingsSection, Umbraco.Core" requirePermission="false" xdt:Locator="Match(name)" xdt:Transform="InsertIfMissing" />
-      <section name="FileSystemProviders" type="Umbraco.Core.Configuration.FileSystemProvidersSection, Umbraco.Core" requirePermission="false" xdt:Locator="Match(name)" xdt:Transform="InsertIfMissing" />
-      <section name="dashBoard" type="Umbraco.Core.Configuration.Dashboard.DashboardSection, Umbraco.Core" requirePermission="false" xdt:Locator="Match(name)" xdt:Transform="InsertIfMissing" />
+      <section name="dashBoard" xdt:Locator="Match(name)" xdt:Transform="Remove" />
      <section name="HealthChecks" type="Umbraco.Core.Configuration.HealthChecks.HealthChecksSection, Umbraco.Core" requirePermission="false" xdt:Locator="Match(name)" xdt:Transform="InsertIfMissing" />
    </sectionGroup>
  </configSections>
@@ -22,26 +16,18 @@
    <add key="owin:appStartup" value="UmbracoDefaultOwinStartup" xdt:Locator="Match(key)" xdt:Transform="InsertIfMissing" />
 	<add key="Umbraco.ModelsBuilder.Enable" value="false" xdt:Locator="Match(key)" xdt:Transform="InsertIfMissing" />
 	<add key="Umbraco.ModelsBuilder.ModelsMode" value="Nothing" xdt:Locator="Match(key)" xdt:Transform="InsertIfMissing" />
-	<add key="umbracoDefaultUILanguage" value="en-US" xdt:Locator="Match(key)" xdt:Transform="SetAttributes(value)" />
  </appSettings>

  <umbracoConfiguration xdt:Transform="InsertIfMissing">
    <settings configSource="config\umbracoSettings.config" xdt:Locator="Match(configSource)" xdt:Transform="InsertIfMissing" />
-    <FileSystemProviders configSource="config\FileSystemProviders.config" xdt:Locator="Match(configSource)" xdt:Transform="InsertIfMissing" />
-    <dashBoard configSource="config\Dashboard.config" xdt:Locator="Match(configSource)" xdt:Transform="InsertIfMissing" />
+    <dashBoard configSource="config\Dashboard.config" xdt:Locator="Match(configSource)" xdt:Transform="Remove" />
    <HealthChecks configSource="config\HealthChecks.config" xdt:Locator="Match(configSource)" xdt:Transform="InsertIfMissing" />
  </umbracoConfiguration>

-  <FileSystemProviders xdt:Transform="Remove" />
-
  <system.data xdt:Transform="InsertIfMissing">
    <DbProviderFactories xdt:Transform="InsertIfMissing">
      <remove invariant="System.Data.SqlServerCe.4.0" xdt:Locator="Match(invariant)" xdt:Transform="InsertIfMissing" />
      <add name="Microsoft SQL Server Compact Data Provider 4.0" invariant="System.Data.SqlServerCe.4.0" description=".NET Framework Data Provider for Microsoft SQL Server Compact" type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe" xdt:Locator="Match(invariant)" xdt:Transform="SetAttributes(invariant,description,type)" />
-      <remove invariant="MySql.Data.MySqlClient" xdt:Locator="Match(invariant)" xdt:Transform="InsertIfMissing" />
-      <add invariant="MySql.Data.MySqlClient" xdt:Locator="Match(invariant)" xdt:Transform="Remove" />
-      <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data" xdt:Locator="Match(invariant)" xdt:Transform="InsertIfMissing" />
-      <add invariant="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data" xdt:Locator="Match(invariant)" xdt:Transform="SetAttributes(type)" />
    </DbProviderFactories>
  </system.data>
  <clientDependency xdt:Transform="RemoveAttributes(version)" />
@@ -49,14 +35,9 @@
  <system.web xdt:Transform="InsertIfMissing" />
  <system.web>
    <siteMap xdt:Transform="Remove" />
-    <siteMap xdt:Transform="InsertIfMissing">
-      <providers xdt:Transform="InsertIfMissing">
-        <remove name="MySqlSiteMapProvider"  xdt:Transform="InsertIfMissing" />
-      </providers>
-    </siteMap>
    <httpRuntime xdt:Transform="InsertIfMissing" />
    <httpRuntime maxRequestLength="51200" fcnMode="Single" xdt:Transform="SetAttributes(fcnMode,maxRequestLength)" />
-    <httpRuntime targetFramework="4.5" xdt:Locator="Condition(count(@targetFramework) != 1)" xdt:Transform="SetAttributes(targetFramework)" />
+    <httpRuntime targetFramework="4.7.2" xdt:Locator="Condition(count(@targetFramework) != 1)" xdt:Transform="SetAttributes(targetFramework)" />

    <membership defaultProvider="DefaultMembershipProvider" xdt:Locator="Match(defaultProvider)" xdt:Transform="Remove" />
    <roleManager defaultProvider="DefaultRoleProvider" xdt:Locator="Match(defaultProvider)" xdt:Transform="Remove"/>
@@ -73,7 +73,6 @@ if ($project) {
 		if(Test-Path $umbracoBinFolder\Microsoft.Web.Helpers.dll) { Remove-Item $umbracoBinFolder\Microsoft.Web.Helpers.dll -Force -Confirm:$false }
 		if(Test-Path $umbracoBinFolder\Microsoft.Web.Mvc.FixedDisplayModes.dll) { Remove-Item $umbracoBinFolder\Microsoft.Web.Mvc.FixedDisplayModes.dll -Force -Confirm:$false }
 		if(Test-Path $umbracoBinFolder\MiniProfiler.dll) { Remove-Item $umbracoBinFolder\MiniProfiler.dll -Force -Confirm:$false }
-		if(Test-Path $umbracoBinFolder\MySql.Data.dll) { Remove-Item $umbracoBinFolder\MySql.Data.dll -Force -Confirm:$false }
 		if(Test-Path $umbracoBinFolder\Newtonsoft.Json.dll) { Remove-Item $umbracoBinFolder\Newtonsoft.Json.dll -Force -Confirm:$false }
 		if(Test-Path $umbracoBinFolder\Owin.dll) { Remove-Item $umbracoBinFolder\Owin.dll -Force -Confirm:$false }
 		if(Test-Path $umbracoBinFolder\Semver.dll) { Remove-Item $umbracoBinFolder\Semver.dll -Force -Confirm:$false }
@@ -54,7 +54,7 @@ if ($project) {
 			[xml]$config = Get-Content $destinationWebConfig
 			
 			$config.configuration.appSettings.ChildNodes | ForEach-Object { 
-				if($_.key -eq "umbracoConfigurationStatus") 
+				if($_.key -eq "Umbraco.Core.ConfigurationStatus") 
 				{
 					# The web.config has an umbraco-specific appSetting in it
 					# don't overwrite it and let config transforms do their thing
@@ -77,10 +77,6 @@ if ($project) {
 		$splashesDestination = Join-Path $projectPath "Config\splashes\"
 		New-Item $splashesDestination -Type directory
 		Copy-Item $splashesSource $splashesDestination -Force
-        
-		$umbracoUIXMLSource = Join-Path $installPath "UmbracoFiles\Umbraco\Config\Create\UI.xml"
-		$umbracoUIXMLDestination = Join-Path $projectPath "Umbraco\Config\Create\UI.xml"
-		Copy-Item $umbracoUIXMLSource $umbracoUIXMLDestination -Force
 	} else {
 		# This part only runs for upgrades
 	
@@ -102,31 +98,6 @@ if ($project) {
 		{
 			# Not a big problem if this fails, let it go
 		}
-		
-		Try 
-		{
-			$uiXmlConfigPath = Join-Path $umbracoFolder -ChildPath "Config" | Join-Path -ChildPath "create" | Join-Path -ChildPath "UI.xml"
-			$uiXmlFile = Join-Path $umbracoFolder -ChildPath "Config" | Join-Path -ChildPath "create" | Join-Path -ChildPath "UI.xml"
-
-			$uiXml = New-Object System.Xml.XmlDocument
-			$uiXml.PreserveWhitespace = $true
-
-			$uiXml.Load($uiXmlFile)
-			$createExists = $uiXml.SelectNodes("//nodeType[@alias='macros']/tasks/create")
-
-			if($createExists.Count -eq 0) 
-			{    
-				$macrosTasksNode = $uiXml.SelectNodes("//nodeType[@alias='macros']/tasks")
-
-				#Creating: <create assembly="umbraco" type="macroTasks" />
-				$createNode = $uiXml.CreateElement("create")
-				$createNode.SetAttribute("assembly", "umbraco")
-				$createNode.SetAttribute("type", "macroTasks")
-				$macrosTasksNode.AppendChild($createNode)
-				$uiXml.Save($uiXmlFile)
-			}
-		} 
-		Catch { }
 	}
 	
 	$installFolder = Join-Path $projectPath "Install"
@@ -1,20 +0,0 @@
-<?xml version="1.0"?>
-<log4net xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
-  <appender name="AsynchronousLog4NetAppender" xdt:Transform="Remove" xdt:Locator="Match(name)" /> 
-  <appender name="AsynchronousLog4NetAppender" type="Umbraco.Core.Logging.ParallelForwardingAppender,Umbraco.Core" xdt:Transform="Insert" >
-    <appender-ref ref="rollingFile" />
-  </appender>
-  
-  <appender name="rollingFile" type="log4net.Appender.RollingFileAppender" xdt:Transform="InsertIfMissing">
-    <file value="App_Data\Logs\UmbracoTraceLog.txt" />
-    <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
-    <appendToFile value="true" />
-    <rollingStyle value="Date" />
-    <maximumFileSize value="5MB" />
-    <layout type="log4net.Layout.PatternLayout">
-      <conversionPattern value=" %date [P%property{processId}/D%property{appDomainId}/T%thread] %-5level %logger - %message%newline" />
-    </layout>
-    <encoding value="utf-8" />
-  </appender>
-</log4net>
-
@@ -1,143 +0,0 @@
-<?xml version="1.0"?>
-<trees xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
-  <!--Content-->
-  <add alias="content" application="content"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="RemoveAttributes(silent)" />
-  <add initialize="false" sortOrder="0" alias="contentRecycleBin" application="content" title="Recycle Bin" iconClosed="icon-folder" iconOpen="icon-folder" type="umbraco.cms.presentation.Trees.ContentRecycleBin, Umbraco.Web" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add initialize="true" sortOrder="0" alias="content" application="content" title="Content" iconClosed="icon-folder" iconOpen="icon-folder" type="Umbraco.Web.Trees.ContentTreeController, Umbraco.Web" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  
-  <!--Media-->
-  <add initialize="true" sortOrder="0" alias="media" application="media" title="Media" iconClosed="icon-folder" iconOpen="icon-folder" type="Umbraco.Web.Trees.MediaTreeController, Umbraco.Web" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add initialize="false" sortOrder="0" alias="mediaRecycleBin" application="media" title="Recycle Bin" iconClosed="icon-folder" iconOpen="icon-folder" type="umbraco.cms.presentation.Trees.MediaRecycleBin, Umbraco.Web" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  
-  <!--Settings-->
-  <add application="settings" alias="nodeTypes"  
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="Remove" />
-  <add initialize="true" sortOrder="0" alias="documentTypes" application="settings" title="Document Types" iconClosed="icon-folder" iconOpen="icon-folder-open" type="Umbraco.Web.Trees.ContentTypeTreeController, Umbraco.Web"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="InsertIfMissing" />
-  <add application="settings" alias="stylesheets" title="Stylesheets" type="umbraco.loadStylesheets, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder" sortOrder="3" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add application="settings" alias="stylesheetProperty" title="Stylesheet Property" type="umbraco.loadStylesheetProperty, Umbraco.Web" iconClosed="" iconOpen="" initialize="false" sortOrder="0" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add application="settings" alias="templates" title="Templates" type="Umbraco.Web.Trees.TemplatesTreeController, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder-open" sortOrder="1" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" /> 
-  
-  <add application="settings" alias="partialViews" type="Umbraco.Web.Trees.PartialViewsTree, Umbraco.Web"
-       xdt:Locator="Match(application,alias,type)"
-       xdt:Transform="Remove()" />
-  <add application="settings" alias="partialViews" title="Partial Views" silent="false" initialize="true" iconClosed="icon-folder" iconOpen="icon-folder" type="Umbraco.Web.Trees.PartialViewsTreeController, Umbraco.Web" sortOrder="2"
-       xdt:Locator="Match(application,alias)"
-       xdt:Transform="InsertIfMissing"  />
-  
-  <add application="settings" alias="scripts" title="Scripts" type="Umbraco.Web.Trees.ScriptTreeController, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder" sortOrder="4" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add application="settings" alias="dictionary" title="Dictionary" type="Umbraco.Web.Trees.DictionaryTreeController, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder" sortOrder="8" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add alias="dictionary" application="settings"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="RemoveAttributes(action)" />
-  <add application="settings" alias="languages" title="Languages" type="Umbraco.Web.Trees.LanguageTreeController, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder-open" sortOrder="5" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add application="settings" initialize="true" alias="mediaTypes" title="Media Types" type="Umbraco.Web.Trees.MediaTypeTreeController, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder-open" sortOrder="7" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-
-  <!--Developer-->
-  <add alias="packager" application="developer"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="Remove" />
-  <add alias="packagerPackages" application="developer"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="Remove" />
-  <add initialize="true" sortOrder="0" alias="packager" application="developer" iconClosed="icon-folder" iconOpen="icon-folder-open" type="Umbraco.Web.Trees.PackagesTreeController, Umbraco.Web" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="InsertIfMissing"  />
-  
-  <!-- Before 7.4 this tree had the alias 'dataType', without the 's' on the end, this is here to rename it  -->
-  <add sortOrder="1" alias="dataTypes" application="developer" type="Umbraco.Web.Trees.DataTypeTreeController, Umbraco.Web"
-       xdt:Locator="Match(application,type)" 
-       xdt:Transform="SetAttributes(alias,sortOrder)" />
-	   
-  <!-- Yes, set the sortOrder again, like above because.. sometimes apparently we already have a dataTypes node and we can't remove more than one.. if they're equal though (same alias,application and sortOrder) it doesn't throw an error -->   
-  <add sortOrder="1" alias="dataTypes" application="developer"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes(sortOrder)" />
-
-  <add initialize="true" sortOrder="2" alias="macros" application="developer" iconClosed="icon-folder" iconOpen="icon-folder-open" type="Umbraco.Web.Trees.MacroTreeController, Umbraco.Web"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add application="developer" alias="relationTypes" title="Relation Types" type="umbraco.loadRelationTypes, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder" sortOrder="4" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  
-  <add application="developer" alias="partialViewMacros" type="Umbraco.Web.Trees.PartialViewMacrosTree, Umbraco.Web"
-       xdt:Locator="Match(application,alias,type)" 
-       xdt:Transform="Remove()" />
-  <add application="developer" alias="partialViewMacros" type="Umbraco.Web.Trees.PartialViewMacrosTreeController, Umbraco.Web" silent="false" initialize="true" sortOrder="6" title="Partial View Macro Files" iconClosed="icon-folder" iconOpen="icon-folder"
-       xdt:Locator="Match(application,alias)"
-       xdt:Transform="InsertIfMissing"  />
-  
-  <add application="developer" alias="python" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="Remove" />
-
-  <!--Users-->
- <add initialize="true" sortOrder="0" alias="users" application="users" iconClosed="icon-folder" iconOpen="icon-folder-open" type="Umbraco.Web.Trees.UserTreeController, Umbraco.Web" 
-      xdt:Locator="Match(application,alias)"
-      xdt:Transform="SetAttributes()" />
-
-  <add application="users" alias="userTypes"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="Remove" />
-  <add application="users" alias="userPermissions" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="Remove" />
-
-  <!--Members-->
-  <add initialize="true" sortOrder="0" alias="member" application="member" title="Members" iconClosed="icon-folder" iconOpen="icon-folder-open" type="Umbraco.Web.Trees.MemberTreeController, Umbraco.Web" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add application="member" alias="memberGroup"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="Remove" />
-  <add application="member" sortOrder="2" alias="memberGroups" title="Member Groups" type="umbraco.loadMemberGroups, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="InsertIfMissing" />
-  <add application="member" alias="memberType"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="Remove" />
-  <add application="member" sortOrder="1" alias="memberTypes" initialize="true" title="Member Types" type="Umbraco.Web.Trees.MemberTypeTreeController, Umbraco.Web" iconClosed="icon-folder" iconOpen="icon-folder-open" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="InsertIfMissing" />
-
-  <!--Translation-->
-  <add silent="false" initialize="true" sortOrder="1" alias="openTasks" application="translation" title="Tasks assigned to you" iconClosed="icon-folder" iconOpen="icon-folder" type="umbraco.loadOpenTasks, Umbraco.Web" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add alias="openTasks" application="translation"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="RemoveAttributes(action)" />
-  <add silent="false" initialize="true" sortOrder="2" alias="yourTasks" application="translation" title="Tasks created by you" iconClosed="icon-folder" iconOpen="icon-folder" type="umbraco.loadYourTasks, Umbraco.Web" 
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="SetAttributes()" />
-  <add alias="yourTasks" application="translation"
-       xdt:Locator="Match(application,alias)" 
-       xdt:Transform="RemoveAttributes(action)" />
-</trees>
@@ -43,14 +43,6 @@

    $release = "" + $semver.Major + "." + $semver.Minor + "." + $semver.Patch

-    Write-Host "Update UmbracoVersion.cs"
-    $this.ReplaceFileText("$($this.SolutionRoot)\src\Umbraco.Core\Configuration\UmbracoVersion.cs", `
-      "(\d+)\.(\d+)\.(\d+)(.(\d+))?", `
-      "$release")
-    $this.ReplaceFileText("$($this.SolutionRoot)\src\Umbraco.Core\Configuration\UmbracoVersion.cs", `
-      "CurrentComment => `"(.+)`"", `
-      "CurrentComment => `"$($semver.PreRelease)`"")
-
    Write-Host "Update IIS Express port in csproj"
    $updater = New-Object "Umbraco.Build.ExpressPortUpdater"
    $csproj = "$($this.SolutionRoot)\src\Umbraco.Web.UI\Umbraco.Web.UI.csproj"
@@ -69,7 +61,7 @@
    $global:node_nodepath = $this.ClearEnvVar("NODEPATH")
    $global:node_npmcache = $this.ClearEnvVar("NPM_CONFIG_CACHE")
    $global:node_npmprefix = $this.ClearEnvVar("NPM_CONFIG_PREFIX")
-    
+
    # https://github.com/gruntjs/grunt-contrib-connect/issues/235
    $this.SetEnvVar("NODE_NO_HTTP2", "1")
  })
@@ -81,7 +73,7 @@
    $this.SetEnvVar("NODEPATH", $node_nodepath)
    $this.SetEnvVar("NPM_CONFIG_CACHE", $node_npmcache)
    $this.SetEnvVar("NPM_CONFIG_PREFIX", $node_npmprefix)
-    
+
    $ignore = $this.ClearEnvVar("NODE_NO_HTTP2")
  })

@@ -100,44 +92,40 @@
    # so we have to take care of it else they'll bubble and kill the build
    if ($error.Count -gt 0) { return }

-    Push-Location "$($this.SolutionRoot)\src\Umbraco.Web.UI.Client"
-    Write-Output "" > $log
+    try {
+        Push-Location "$($this.SolutionRoot)\src\Umbraco.Web.UI.Client"
+        Write-Output "" > $log

-    Write-Output "### node version is:" > $log
-    &node -v >> $log 2>&1
-    if (-not $?) { throw "Failed to report node version." }
+        Write-Output "### node version is:" > $log
+        node -v >> $log 2>&1
+        if (-not $?) { throw "Failed to report node version." }

-    Write-Output "### npm version is:" >> $log 2>&1
-    &npm -v >> $log 2>&1
-    if (-not $?) { throw "Failed to report npm version." }
+        Write-Output "### npm version is:" >> $log 2>&1
+        npm -v >> $log 2>&1
+        if (-not $?) { throw "Failed to report npm version." }

-    Write-Output "### clean npm cache" >> $log 2>&1
-    &npm cache clean --force >> $log 2>&1
-    $error.Clear() # that one can fail 'cos security bug - ignore
+        Write-Output "### clean npm cache" >> $log 2>&1
+        npm cache clean --force >> $log 2>&1
+        $error.Clear() # that one can fail 'cos security bug - ignore

-    Write-Output "### npm install" >> $log 2>&1
-    &npm install >> $log 2>&1
-    Write-Output ">> $? $($error.Count)" >> $log 2>&1
+        Write-Output "### npm install" >> $log 2>&1
+        npm install >> $log 2>&1
+        Write-Output ">> $? $($error.Count)" >> $log 2>&1
+        # Don't really care about the messages from npm install making us think there are errors
+        $error.Clear()

-    Write-Output "### install gulp" >> $log 2>&1
-    &npm install -g gulp >> $log 2>&1
-    $error.Clear() # that one fails 'cos deprecated stuff - ignore
+        Write-Output "### gulp build for version $($this.Version.Release)" >> $log 2>&1
+        npx gulp build --buildversion=$this.Version.Release >> $log 2>&1
+        if (-not $?) { throw "Failed to build" } # that one is expected to work
+    } finally {
+        Pop-Location

-    Write-Output "### install gulp-cli" >> $log 2>&1
-    &npm install -g gulp-cli --quiet >> $log 2>&1
-    $error.Clear() # that one fails 'cos some files not being removed - ignore
+        # FIXME: should we filter the log to find errors?
+        #get-content .\build.tmp\belle.log | %{ if ($_ -match "build") { write $_}}

-    Write-Output "### gulp build for version $($this.Version.Release)" >> $log 2>&1
-    &gulp build --buildversion=$this.Version.Release >> $log 2>&1
-    if (-not $?) { throw "Failed to build" } # that one is expected to work
-
-    Pop-Location
-
-    # fixme - should we filter the log to find errors?
-    #get-content .\build.tmp\belle.log | %{ if ($_ -match "build") { write $_}}
-
-    # restore
-    $this.RestoreNode()
+        # restore
+        $this.RestoreNode()
+    }

    # setting node_modules folder to hidden
    # used to prevent VS13 from crashing on it while loading the websites project
@@ -189,7 +177,7 @@
  {
    Write-Host "Prepare Tests"

-    # fixme - idea is to avoid rebuilding everything for tests
+    # FIXME: - idea is to avoid rebuilding everything for tests
    # but because of our weird assembly versioning (with .* stuff)
    # everything gets rebuilt all the time...
    #Copy-Files "$tmp\bin" "." "$tmp\tests"
@@ -342,9 +330,6 @@

  $ubuild.DefineMethod("PrepareBuild",
  {
-    Write-Host "Clear folders and files"
-    $this.RemoveDirectory("$($this.SolutionRoot)\src\Umbraco.Web.UI.Client\bower_components")
-
    $this.TempStoreFile("$($this.SolutionRoot)\src\Umbraco.Web.UI\web.config")
    Write-Host "Create clean web.config"
    $this.CopyFile("$($this.SolutionRoot)\src\Umbraco.Web.UI\web.Template.config", "$($this.SolutionRoot)\src\Umbraco.Web.UI\web.config")
@@ -434,7 +419,7 @@
    Write-Host "Prepare Azure Gallery"
    $this.CopyFile("$($this.SolutionRoot)\build\Azure\azuregalleryrelease.ps1", $this.BuildOutput)
  })
-  
+
  $ubuild.DefineMethod("Build",
  {
    $error.Clear()
@@ -464,9 +449,22 @@
    if ($this.OnError()) { return }
    $this.PrepareAzureGallery()
    if ($this.OnError()) { return }
+    $this.PostPackageHook()
+    if ($this.OnError()) { return }
    Write-Host "Done"
  })

+  $ubuild.DefineMethod("PostPackageHook",
+  {
+    # run hook
+    if ($this.HasMethod("PostPackage"))
+    {
+      Write-Host "Run PostPackage hook"
+      $this.PostPackage();
+      if (-not $?) { throw "Failed to run hook." }
+    }
+  })
+
  # ################################################################
  # RUN
  # ################################################################
@@ -7,7 +7,7 @@
      <span class="pull-right">
        <a href="#top">Back to top</a>
      </span>
-      <span>Copyright © 2016 Umbraco<br>Generated by <strong>DocFX</strong></span>
+      <span>Copyright © 2016-present Umbraco<br>Generated by <strong>DocFX</strong></span>
    </div>
  </div>
 </footer>
@@ -2,7 +2,7 @@
 using System.Resources;

 [assembly: AssemblyCompany("Umbraco")]
-[assembly: AssemblyCopyright("Copyright © Umbraco 2018")]
+[assembly: AssemblyCopyright("Copyright © Umbraco 2019")]
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]

@@ -19,4 +19,4 @@ using System.Resources;

 // these are FYI and changed automatically
 [assembly: AssemblyFileVersion("8.0.0")]
-[assembly: AssemblyInformationalVersion("8.0.0-alpha.52")]
+[assembly: AssemblyInformationalVersion("8.0.0-alpha.58")]
@@ -8,7 +8,7 @@ namespace Umbraco.Core
    public static class Attempt
    {
        // note:
-        // cannot rely on overloads only to differenciate between with/without status
+        // cannot rely on overloads only to differentiate between with/without status
        // in some cases it will always be ambiguous, so be explicit w/ 'WithStatus' methods

        /// <summary>
@@ -121,7 +121,7 @@ namespace Umbraco.Core
        }

        /// <summary>
-        /// Implicity operator to check if the attempt was successful without having to access the 'success' property
+        /// Implicitly operator to check if the attempt was successful without having to access the 'success' property
        /// </summary>
        /// <param name="a"></param>
        /// <returns></returns>
@@ -130,7 +130,7 @@ namespace Umbraco.Core
        }

        /// <summary>
-        /// Implicity operator to check if the attempt was successful without having to access the 'success' property
+        /// Implicitly operator to check if the attempt was successful without having to access the 'success' property
        /// </summary>
        /// <param name="a"></param>
        /// <returns></returns>
@@ -1,39 +0,0 @@
-namespace Umbraco.Core
-{
-    public static class ByteArrayExtensions
-    {
-        private static readonly char[] BytesToHexStringLookup = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
-
-        public static string ToHexString(this byte[] bytes)
-        {
-            int i = 0, p = 0, bytesLength = bytes.Length;
-            var chars = new char[bytesLength * 2];
-            while (i < bytesLength)
-            {
-                var b = bytes[i++];
-                chars[p++] = BytesToHexStringLookup[b / 0x10];
-                chars[p++] = BytesToHexStringLookup[b % 0x10];
-            }
-            return new string(chars, 0, chars.Length);
-        }
-
-        public static string ToHexString(this byte[] bytes, char separator, int blockSize, int blockCount)
-        {
-            int p = 0, bytesLength = bytes.Length, count = 0, size = 0;
-            var chars = new char[bytesLength * 2 + blockCount];
-            for (var i = 0; i < bytesLength; i++)
-            {
-                var b = bytes[i++];
-                chars[p++] = BytesToHexStringLookup[b / 0x10];
-                chars[p++] = BytesToHexStringLookup[b % 0x10];
-                if (count == blockCount) continue;
-                if (++size < blockSize) continue;
-
-                chars[p++] = '/';
-                size = 0;
-                count++;
-            }
-            return new string(chars, 0, chars.Length);
-        }
-    }
-}
@@ -8,9 +8,9 @@ namespace Umbraco.Core.Cache
    /// <summary>
    /// Extensions for strongly typed access
    /// </summary>
-    public static class CacheProviderExtensions
+    public static class AppCacheExtensions
    {
-        public static T GetCacheItem<T>(this IRuntimeCacheProvider provider,
+        public static T GetCacheItem<T>(this IAppPolicyCache provider,
            string cacheKey,
            Func<T> getCacheItem,
            TimeSpan? timeout,
@@ -19,11 +19,11 @@ namespace Umbraco.Core.Cache
            CacheItemRemovedCallback removedCallback = null,
            string[] dependentFiles = null)
        {
-            var result = provider.GetCacheItem(cacheKey, () => getCacheItem(), timeout, isSliding, priority, removedCallback, dependentFiles);
+            var result = provider.Get(cacheKey, () => getCacheItem(), timeout, isSliding, priority, removedCallback, dependentFiles);
            return result == null ? default(T) : result.TryConvertTo<T>().Result;
        }

-        public static void InsertCacheItem<T>(this IRuntimeCacheProvider provider,
+        public static void InsertCacheItem<T>(this IAppPolicyCache provider,
            string cacheKey,
            Func<T> getCacheItem,
            TimeSpan? timeout = null,
@@ -32,24 +32,24 @@ namespace Umbraco.Core.Cache
            CacheItemRemovedCallback removedCallback = null,
            string[] dependentFiles = null)
        {
-            provider.InsertCacheItem(cacheKey, () => getCacheItem(), timeout, isSliding, priority, removedCallback, dependentFiles);
+            provider.Insert(cacheKey, () => getCacheItem(), timeout, isSliding, priority, removedCallback, dependentFiles);
        }

-        public static IEnumerable<T> GetCacheItemsByKeySearch<T>(this ICacheProvider provider, string keyStartsWith)
+        public static IEnumerable<T> GetCacheItemsByKeySearch<T>(this IAppCache provider, string keyStartsWith)
        {
-            var result = provider.GetCacheItemsByKeySearch(keyStartsWith);
+            var result = provider.SearchByKey(keyStartsWith);
            return result.Select(x => x.TryConvertTo<T>().Result);
        }

-        public static IEnumerable<T> GetCacheItemsByKeyExpression<T>(this ICacheProvider provider, string regexString)
+        public static IEnumerable<T> GetCacheItemsByKeyExpression<T>(this IAppCache provider, string regexString)
        {
-            var result = provider.GetCacheItemsByKeyExpression(regexString);
+            var result = provider.SearchByRegex(regexString);
            return result.Select(x => x.TryConvertTo<T>().Result);
        }

-        public static T GetCacheItem<T>(this ICacheProvider provider, string cacheKey)
+        public static T GetCacheItem<T>(this IAppCache provider, string cacheKey)
        {
-            var result = provider.GetCacheItem(cacheKey);
+            var result = provider.Get(cacheKey);
            if (result == null)
            {
                return default(T);
@@ -57,9 +57,9 @@ namespace Umbraco.Core.Cache
            return result.TryConvertTo<T>().Result;
        }

-        public static T GetCacheItem<T>(this ICacheProvider provider, string cacheKey, Func<T> getCacheItem)
+        public static T GetCacheItem<T>(this IAppCache provider, string cacheKey, Func<T> getCacheItem)
        {
-            var result = provider.GetCacheItem(cacheKey, () => getCacheItem());
+            var result = provider.Get(cacheKey, () => getCacheItem());
            if (result == null)
            {
                return default(T);
@@ -0,0 +1,86 @@
+using System;
+using System.Web;
+
+namespace Umbraco.Core.Cache
+{
+    /// <summary>
+    /// Represents the application caches.
+    /// </summary>
+    public class AppCaches
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AppCaches"/> for use in a web application.
+        /// </summary>
+        public AppCaches()
+            : this(HttpRuntime.Cache)
+        { }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AppCaches"/> for use in a web application.
+        /// </summary>
+        public AppCaches(System.Web.Caching.Cache cache)
+            : this(
+                new WebCachingAppCache(cache),
+                new HttpRequestAppCache(),
+                new IsolatedCaches(t => new ObjectCacheAppCache()))
+        { }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AppCaches"/> with cache providers.
+        /// </summary>
+        public AppCaches(
+            IAppPolicyCache runtimeCache,
+            IAppCache requestCache,
+            IsolatedCaches isolatedCaches)
+        {
+            RuntimeCache = runtimeCache ?? throw new ArgumentNullException(nameof(runtimeCache));
+            RequestCache = requestCache ?? throw new ArgumentNullException(nameof(requestCache));
+            IsolatedCaches = isolatedCaches ?? throw new ArgumentNullException(nameof(isolatedCaches));
+        }
+
+        /// <summary>
+        /// Gets the special disabled instance.
+        /// </summary>
+        /// <remarks>
+        /// <para>When used by repositories, all cache policies apply, but the underlying caches do not cache anything.</para>
+        /// <para>Used by tests.</para>
+        /// </remarks>
+        public static AppCaches Disabled { get; } = new AppCaches(NoAppCache.Instance, NoAppCache.Instance, new IsolatedCaches(_ => NoAppCache.Instance));
+
+        /// <summary>
+        /// Gets the special no-cache instance.
+        /// </summary>
+        /// <remarks>
+        /// <para>When used by repositories, all cache policies are bypassed.</para>
+        /// <para>Used by repositories that do no cache.</para>
+        /// </remarks>
+        public static AppCaches NoCache { get; } = new AppCaches(NoAppCache.Instance, NoAppCache.Instance, new IsolatedCaches(_ => NoAppCache.Instance));
+
+        /// <summary>
+        /// Gets the per-request cache.
+        /// </summary>
+        /// <remarks>
+        /// <para>The per-request caches works on top of the current HttpContext items.</para>
+        /// <para>Outside a web environment, the behavior of that cache is unspecified.</para>
+        /// </remarks>
+        public IAppCache RequestCache { get; }
+
+        /// <summary>
+        /// Gets the runtime cache.
+        /// </summary>
+        /// <remarks>
+        /// <para>The runtime cache is the main application cache.</para>
+        /// </remarks>
+        public IAppPolicyCache RuntimeCache { get; }
+
+        /// <summary>
+        /// Gets the isolated caches.
+        /// </summary>
+        /// <remarks>
+        /// <para>Isolated caches are used by e.g. repositories, to ensure that each cached entity
+        /// type has its own cache, so that lookups are fast and the repository does not need to
+        /// search through all keys on a global scale.</para>
+        /// </remarks>
+        public IsolatedCaches IsolatedCaches { get; }
+    }
+}
@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Concurrent;
+
+namespace Umbraco.Core.Cache
+{
+    /// <summary>
+    /// Provides a base class for implementing a dictionary of <see cref="IAppPolicyCache"/>.
+    /// </summary>
+    /// <typeparam name="TKey">The type of the dictionary key.</typeparam>
+    public abstract class AppPolicedCacheDictionary<TKey>
+    {
+        private readonly ConcurrentDictionary<TKey, IAppPolicyCache> _caches = new ConcurrentDictionary<TKey, IAppPolicyCache>();
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AppPolicedCacheDictionary{TKey}"/> class.
+        /// </summary>
+        /// <param name="cacheFactory"></param>
+        protected AppPolicedCacheDictionary(Func<TKey, IAppPolicyCache> cacheFactory)
+        {
+            CacheFactory = cacheFactory;
+        }
+
+        /// <summary>
+        /// Gets the internal cache factory, for tests only!
+        /// </summary>
+        internal readonly Func<TKey, IAppPolicyCache> CacheFactory;
+
+        /// <summary>
+        /// Gets or creates a cache.
+        /// </summary>
+        public IAppPolicyCache GetOrCreate(TKey key)
+            => _caches.GetOrAdd(key, k => CacheFactory(k));
+
+        /// <summary>
+        /// Tries to get a cache.
+        /// </summary>
+        public Attempt<IAppPolicyCache> Get(TKey key)
+            => _caches.TryGetValue(key, out var cache) ? Attempt.Succeed(cache) : Attempt.Fail<IAppPolicyCache>();
+
+        /// <summary>
+        /// Removes a cache.
+        /// </summary>
+        public void Remove(TKey key)
+        {
+            _caches.TryRemove(key, out _);
+        }
+
+        /// <summary>
+        /// Removes all caches.
+        /// </summary>
+        public void RemoveAll()
+        {
+            _caches.Clear();
+        }
+
+        /// <summary>
+        /// Clears a cache.
+        /// </summary>
+        public void ClearCache(TKey key)
+        {
+            if (_caches.TryGetValue(key, out var cache))
+                cache.Clear();
+        }
+
+        /// <summary>
+        /// Clears all caches.
+        /// </summary>
+        public void ClearAllCaches()
+        {
+            foreach (var cache in _caches.Values)
+                cache.Clear();
+        }
+    }
+}
@@ -1,99 +0,0 @@
-using System;
-using System.Web;
-
-namespace Umbraco.Core.Cache
-{
-    /// <summary>
-    /// Class that is exposed by the ApplicationContext for application wide caching purposes
-    /// </summary>
-    public class CacheHelper
-    {
-        public static CacheHelper NoCache { get; } = new CacheHelper(NullCacheProvider.Instance, NullCacheProvider.Instance, NullCacheProvider.Instance, new IsolatedRuntimeCache(_ => NullCacheProvider.Instance));
-
-        /// <summary>
-        /// Creates a cache helper with disabled caches
-        /// </summary>
-        /// <returns></returns>
-        /// <remarks>
-        /// Good for unit testing
-        /// </remarks>
-        public static CacheHelper CreateDisabledCacheHelper()
-        {
-            // do *not* return NoCache
-            // NoCache is a special instance that is detected by RepositoryBase and disables all cache policies
-            // CreateDisabledCacheHelper is used in tests to use no cache, *but* keep all cache policies
-            return new CacheHelper(NullCacheProvider.Instance, NullCacheProvider.Instance, NullCacheProvider.Instance, new IsolatedRuntimeCache(_ => NullCacheProvider.Instance));
-        }
-
-        /// <summary>
-        /// Initializes a new instance for use in the web
-        /// </summary>
-        public CacheHelper()
-            : this(
-                new HttpRuntimeCacheProvider(HttpRuntime.Cache),
-                new StaticCacheProvider(),
-                new HttpRequestCacheProvider(),
-                new IsolatedRuntimeCache(t => new ObjectCacheRuntimeCacheProvider()))
-        {
-        }
-
-        /// <summary>
-        /// Initializes a new instance for use in the web
-        /// </summary>
-        /// <param name="cache"></param>
-        public CacheHelper(System.Web.Caching.Cache cache)
-            : this(
-                new HttpRuntimeCacheProvider(cache),
-                new StaticCacheProvider(),
-                new HttpRequestCacheProvider(),
-                new IsolatedRuntimeCache(t => new ObjectCacheRuntimeCacheProvider()))
-        {
-        }
-
-
-        /// <summary>
-        /// Initializes a new instance based on the provided providers
-        /// </summary>
-        /// <param name="httpCacheProvider"></param>
-        /// <param name="staticCacheProvider"></param>
-        /// <param name="requestCacheProvider"></param>
-        /// <param name="isolatedCacheManager"></param>
-        public CacheHelper(
-            IRuntimeCacheProvider httpCacheProvider,
-            ICacheProvider staticCacheProvider,
-            ICacheProvider requestCacheProvider,
-            IsolatedRuntimeCache isolatedCacheManager)
-        {
-            if (httpCacheProvider == null) throw new ArgumentNullException("httpCacheProvider");
-            if (staticCacheProvider == null) throw new ArgumentNullException("staticCacheProvider");
-            if (requestCacheProvider == null) throw new ArgumentNullException("requestCacheProvider");
-            if (isolatedCacheManager == null) throw new ArgumentNullException("isolatedCacheManager");
-            RuntimeCache = httpCacheProvider;
-            StaticCache = staticCacheProvider;
-            RequestCache = requestCacheProvider;
-            IsolatedRuntimeCache = isolatedCacheManager;
-        }
-
-        /// <summary>
-        /// Returns the current Request cache
-        /// </summary>
-        public ICacheProvider RequestCache { get; internal set; }
-
-        /// <summary>
-        /// Returns the current Runtime cache
-        /// </summary>
-        public ICacheProvider StaticCache { get; internal set; }
-
-        /// <summary>
-        /// Returns the current Runtime cache
-        /// </summary>
-        public IRuntimeCacheProvider RuntimeCache { get; internal set; }
-
-        /// <summary>
-        /// Returns the current Isolated Runtime cache manager
-        /// </summary>
-        public IsolatedRuntimeCache IsolatedRuntimeCache { get; internal set; }
-
-    }
-
-}
@@ -5,10 +5,10 @@
    /// </summary>
    public static class CacheKeys
    {
-        public const string ApplicationTreeCacheKey = "ApplicationTreeCache"; // used by ApplicationTreeService
        public const string ApplicationsCacheKey = "ApplicationCache"; // used by SectionService

-        public const string TemplateFrontEndCacheKey = "template"; // fixme usage?
+        // TODO: this one can probably be removed
+        public const string TemplateFrontEndCacheKey = "template";

        public const string MacroContentCacheKey = "macroContent_"; // used in MacroRenderers
    }
@@ -16,10 +16,10 @@ namespace Umbraco.Core.Cache
        /// <summary>
        /// Initializes a new instance of the <see cref="CacheRefresherBase{TInstanceType}"/>.
        /// </summary>
-        /// <param name="cacheHelper">A cache helper.</param>
-        protected CacheRefresherBase(CacheHelper cacheHelper)
+        /// <param name="appCaches">A cache helper.</param>
+        protected CacheRefresherBase(AppCaches appCaches)
        {
-            CacheHelper = cacheHelper;
+            AppCaches = appCaches;
        }

        /// <summary>
@@ -93,7 +93,7 @@ namespace Umbraco.Core.Cache
        /// <summary>
        /// Gets the cache helper.
        /// </summary>
-        protected CacheHelper CacheHelper { get; }
+        protected AppCaches AppCaches { get; }

        /// <summary>
        /// Clears the cache for all repository entities of a specified type.
@@ -102,7 +102,7 @@ namespace Umbraco.Core.Cache
        protected void ClearAllIsolatedCacheByEntityType<TEntity>()
            where TEntity : class, IEntity
        {
-            CacheHelper.IsolatedRuntimeCache.ClearCache<TEntity>();
+            AppCaches.IsolatedCaches.ClearCache<TEntity>();
        }

        /// <summary>
@@ -1,15 +1,9 @@
-using System.Collections.Generic;
-using LightInject;
-using Umbraco.Core.Composing;
+using Umbraco.Core.Composing;

 namespace Umbraco.Core.Cache
 {
    public class CacheRefresherCollectionBuilder : LazyCollectionBuilderBase<CacheRefresherCollectionBuilder, CacheRefresherCollection, ICacheRefresher>
    {
-        public CacheRefresherCollectionBuilder(IServiceContainer container)
-            : base(container)
-        { }
-
        protected override CacheRefresherCollectionBuilder This => this;
    }
 }
@@ -0,0 +1,157 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Web.Caching;
+using Umbraco.Core.Models;
+using Umbraco.Core.Models.Entities;
+
+namespace Umbraco.Core.Cache
+{
+    /// <summary>
+    /// Implements <see cref="IAppPolicyCache"/> by wrapping an inner other <see cref="IAppPolicyCache"/>
+    /// instance, and ensuring that all inserts and returns are deep cloned copies of the cache item,
+    /// when the item is deep-cloneable.
+    /// </summary>
+    internal class DeepCloneAppCache : IAppPolicyCache
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="DeepCloneAppCache"/> class.
+        /// </summary>
+        public DeepCloneAppCache(IAppPolicyCache innerCache)
+        {
+            var type = typeof (DeepCloneAppCache);
+
+            if (innerCache.GetType() == type)
+                throw new InvalidOperationException($"A {type} cannot wrap another instance of itself.");
+
+            InnerCache = innerCache;
+        }
+
+        /// <summary>
+        /// Gets the inner cache.
+        /// </summary>
+        public IAppPolicyCache InnerCache { get; }
+
+        /// <inheritdoc />
+        public object Get(string key)
+        {
+            var item = InnerCache.Get(key);
+            return CheckCloneableAndTracksChanges(item);
+        }
+
+        /// <inheritdoc />
+        public object Get(string key, Func<object> factory)
+        {
+            var cached = InnerCache.Get(key, () =>
+            {
+                var result = FastDictionaryAppCacheBase.GetSafeLazy(factory);
+                var value = result.Value; // force evaluation now - this may throw if cacheItem throws, and then nothing goes into cache
+                // do not store null values (backward compat), clone / reset to go into the cache
+                return value == null ? null : CheckCloneableAndTracksChanges(value);
+            });
+            return CheckCloneableAndTracksChanges(cached);
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<object> SearchByKey(string keyStartsWith)
+        {
+            return InnerCache.SearchByKey(keyStartsWith)
+                .Select(CheckCloneableAndTracksChanges);
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<object> SearchByRegex(string regex)
+        {
+            return InnerCache.SearchByRegex(regex)
+                .Select(CheckCloneableAndTracksChanges);
+        }
+
+        /// <inheritdoc />
+        public object Get(string key, Func<object> factory, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
+        {
+            var cached = InnerCache.Get(key, () =>
+            {
+                var result = FastDictionaryAppCacheBase.GetSafeLazy(factory);
+                var value = result.Value; // force evaluation now - this may throw if cacheItem throws, and then nothing goes into cache
+                // do not store null values (backward compat), clone / reset to go into the cache
+                return value == null ? null : CheckCloneableAndTracksChanges(value); 
+
+                // clone / reset to go into the cache
+            }, timeout, isSliding, priority, removedCallback, dependentFiles);
+
+            // clone / reset to go into the cache
+            return CheckCloneableAndTracksChanges(cached);
+        }
+
+        /// <inheritdoc />
+        public void Insert(string key, Func<object> factory, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
+        {
+            InnerCache.Insert(key, () =>
+            {
+                var result = FastDictionaryAppCacheBase.GetSafeLazy(factory);
+                var value = result.Value; // force evaluation now - this may throw if cacheItem throws, and then nothing goes into cache
+                // do not store null values (backward compat), clone / reset to go into the cache
+                return value == null ? null : CheckCloneableAndTracksChanges(value);
+            }, timeout, isSliding, priority, removedCallback, dependentFiles);
+        }
+
+        /// <inheritdoc />
+        public void Clear()
+        {
+            InnerCache.Clear();
+        }
+
+        /// <inheritdoc />
+        public void Clear(string key)
+        {
+            InnerCache.Clear(key);
+        }
+
+        /// <inheritdoc />
+        public void ClearOfType(string typeName)
+        {
+            InnerCache.ClearOfType(typeName);
+        }
+
+        /// <inheritdoc />
+        public void ClearOfType<T>()
+        {
+            InnerCache.ClearOfType<T>();
+        }
+
+        /// <inheritdoc />
+        public void ClearOfType<T>(Func<string, T, bool> predicate)
+        {
+            InnerCache.ClearOfType<T>(predicate);
+        }
+
+        /// <inheritdoc />
+        public void ClearByKey(string keyStartsWith)
+        {
+            InnerCache.ClearByKey(keyStartsWith);
+        }
+
+        /// <inheritdoc />
+        public void ClearByRegex(string regex)
+        {
+            InnerCache.ClearByRegex(regex);
+        }
+
+        private static object CheckCloneableAndTracksChanges(object input)
+        {
+            if (input is IDeepCloneable cloneable)
+            {
+                input = cloneable.DeepClone();
+            }
+
+            // reset dirty initial properties
+            if (input is IRememberBeingDirty tracksChanges)
+            {
+                tracksChanges.ResetDirtyProperties(false);
+                input = tracksChanges;
+            }
+
+            return input;
+        }
+    }
+}
@@ -1,155 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Web.Caching;
-using Umbraco.Core.Models;
-using Umbraco.Core.Models.Entities;
-
-namespace Umbraco.Core.Cache
-{
-    /// <summary>
-    /// Interface describing this cache provider as a wrapper for another
-    /// </summary>
-    internal interface IRuntimeCacheProviderWrapper
-    {
-        IRuntimeCacheProvider InnerProvider { get; }
-    }
-
-    /// <summary>
-    /// A wrapper for any IRuntimeCacheProvider that ensures that all inserts and returns
-    /// are a deep cloned copy of the item when the item is IDeepCloneable and that tracks changes are
-    /// reset if the object is TracksChangesEntityBase
-    /// </summary>
-    internal class DeepCloneRuntimeCacheProvider : IRuntimeCacheProvider, IRuntimeCacheProviderWrapper
-    {
-        public IRuntimeCacheProvider InnerProvider { get; }
-
-        public DeepCloneRuntimeCacheProvider(IRuntimeCacheProvider innerProvider)
-        {
-            var type = typeof (DeepCloneRuntimeCacheProvider);
-
-            if (innerProvider.GetType() == type)
-                throw new InvalidOperationException($"A {type} cannot wrap another instance of {type}.");
-
-            InnerProvider = innerProvider;
-        }
-
-        #region Clear - doesn't require any changes
-
-        public void ClearAllCache()
-        {
-            InnerProvider.ClearAllCache();
-        }
-
-        public void ClearCacheItem(string key)
-        {
-            InnerProvider.ClearCacheItem(key);
-        }
-
-        public void ClearCacheObjectTypes(string typeName)
-        {
-            InnerProvider.ClearCacheObjectTypes(typeName);
-        }
-
-        public void ClearCacheObjectTypes<T>()
-        {
-            InnerProvider.ClearCacheObjectTypes<T>();
-        }
-
-        public void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate)
-        {
-            InnerProvider.ClearCacheObjectTypes<T>(predicate);
-        }
-
-        public void ClearCacheByKeySearch(string keyStartsWith)
-        {
-            InnerProvider.ClearCacheByKeySearch(keyStartsWith);
-        }
-
-        public void ClearCacheByKeyExpression(string regexString)
-        {
-            InnerProvider.ClearCacheByKeyExpression(regexString);
-        }
-
-        #endregion
-
-        public IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith)
-        {
-            return InnerProvider.GetCacheItemsByKeySearch(keyStartsWith)
-                .Select(CheckCloneableAndTracksChanges);
-        }
-
-        public IEnumerable<object> GetCacheItemsByKeyExpression(string regexString)
-        {
-            return InnerProvider.GetCacheItemsByKeyExpression(regexString)
-                .Select(CheckCloneableAndTracksChanges);
-        }
-
-        public object GetCacheItem(string cacheKey)
-        {
-            var item = InnerProvider.GetCacheItem(cacheKey);
-            return CheckCloneableAndTracksChanges(item);
-        }
-
-        public object GetCacheItem(string cacheKey, Func<object> getCacheItem)
-        {
-            var cached = InnerProvider.GetCacheItem(cacheKey, () =>
-            {
-                var result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
-                var value = result.Value; // force evaluation now - this may throw if cacheItem throws, and then nothing goes into cache
-                if (value == null) return null; // do not store null values (backward compat)
-
-                return CheckCloneableAndTracksChanges(value);
-            });
-            return CheckCloneableAndTracksChanges(cached);
-        }
-
-        public object GetCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        {
-            var cached = InnerProvider.GetCacheItem(cacheKey, () =>
-            {
-                var result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
-                var value = result.Value; // force evaluation now - this may throw if cacheItem throws, and then nothing goes into cache
-                if (value == null) return null; // do not store null values (backward compat)
-
-                // clone / reset to go into the cache
-                return CheckCloneableAndTracksChanges(value);
-            }, timeout, isSliding, priority, removedCallback, dependentFiles);
-
-            // clone / reset to go into the cache
-            return CheckCloneableAndTracksChanges(cached);
-        }
-
-        public void InsertCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        {
-            InnerProvider.InsertCacheItem(cacheKey, () =>
-            {
-                var result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
-                var value = result.Value; // force evaluation now - this may throw if cacheItem throws, and then nothing goes into cache
-                if (value == null) return null; // do not store null values (backward compat)
-
-                // clone / reset to go into the cache
-                return CheckCloneableAndTracksChanges(value);
-            }, timeout, isSliding, priority, removedCallback, dependentFiles);
-        }
-
-        private static object CheckCloneableAndTracksChanges(object input)
-        {
-            var cloneable = input as IDeepCloneable;
-            if (cloneable != null)
-            {
-                input = cloneable.DeepClone();
-            }
-
-            // reset dirty initial properties (U4-1946)
-            var tracksChanges = input as IRememberBeingDirty;
-            if (tracksChanges != null)
-            {
-                tracksChanges.ResetDirtyProperties(false);
-                input =  tracksChanges;
-            }
-
-            return input;
-        }
-    }
-}
@@ -23,7 +23,7 @@ namespace Umbraco.Core.Cache
        private static readonly TEntity[] EmptyEntities = new TEntity[0]; // const
        private readonly RepositoryCachePolicyOptions _options;

-        public DefaultRepositoryCachePolicy(IRuntimeCacheProvider cache, IScopeAccessor scopeAccessor, RepositoryCachePolicyOptions options)
+        public DefaultRepositoryCachePolicy(IAppPolicyCache cache, IScopeAccessor scopeAccessor, RepositoryCachePolicyOptions options)
            : base(cache, scopeAccessor)
        {
            _options = options ?? throw new ArgumentNullException(nameof(options));
@@ -42,7 +42,7 @@ namespace Umbraco.Core.Cache

        protected virtual void InsertEntity(string cacheKey, TEntity entity)
        {
-            Cache.InsertCacheItem(cacheKey, () => entity, TimeSpan.FromMinutes(5), true);
+            Cache.Insert(cacheKey, () => entity, TimeSpan.FromMinutes(5), true);
        }

        protected virtual void InsertEntities(TId[] ids, TEntity[] entities)
@@ -52,7 +52,7 @@ namespace Umbraco.Core.Cache
                // getting all of them, and finding nothing.
                // if we can cache a zero count, cache an empty array,
                // for as long as the cache is not cleared (no expiration)
-                Cache.InsertCacheItem(GetEntityTypeCacheKey(), () => EmptyEntities);
+                Cache.Insert(GetEntityTypeCacheKey(), () => EmptyEntities);
            }
            else
            {
@@ -60,7 +60,7 @@ namespace Umbraco.Core.Cache
                foreach (var entity in entities)
                {
                    var capture = entity;
-                    Cache.InsertCacheItem(GetEntityCacheKey(entity.Id), () => capture, TimeSpan.FromMinutes(5), true);
+                    Cache.Insert(GetEntityCacheKey(entity.Id), () => capture, TimeSpan.FromMinutes(5), true);
                }
            }
        }
@@ -77,21 +77,21 @@ namespace Umbraco.Core.Cache
                // just to be safe, we cannot cache an item without an identity
                if (entity.HasIdentity)
                {
-                    Cache.InsertCacheItem(GetEntityCacheKey(entity.Id), () => entity, TimeSpan.FromMinutes(5), true);
+                    Cache.Insert(GetEntityCacheKey(entity.Id), () => entity, TimeSpan.FromMinutes(5), true);
                }

                // if there's a GetAllCacheAllowZeroCount cache, ensure it is cleared
-                Cache.ClearCacheItem(GetEntityTypeCacheKey());
+                Cache.Clear(GetEntityTypeCacheKey());
            }
            catch
            {
                // if an exception is thrown we need to remove the entry from cache,
                // this is ONLY a work around because of the way
                // that we cache entities: http://issues.umbraco.org/issue/U4-4259
-                Cache.ClearCacheItem(GetEntityCacheKey(entity.Id));
+                Cache.Clear(GetEntityCacheKey(entity.Id));

                // if there's a GetAllCacheAllowZeroCount cache, ensure it is cleared
-                Cache.ClearCacheItem(GetEntityTypeCacheKey());
+                Cache.Clear(GetEntityTypeCacheKey());

                throw;
            }
@@ -109,21 +109,21 @@ namespace Umbraco.Core.Cache
                // just to be safe, we cannot cache an item without an identity
                if (entity.HasIdentity)
                {
-                    Cache.InsertCacheItem(GetEntityCacheKey(entity.Id), () => entity, TimeSpan.FromMinutes(5), true);
+                    Cache.Insert(GetEntityCacheKey(entity.Id), () => entity, TimeSpan.FromMinutes(5), true);
                }

                // if there's a GetAllCacheAllowZeroCount cache, ensure it is cleared
-                Cache.ClearCacheItem(GetEntityTypeCacheKey());
+                Cache.Clear(GetEntityTypeCacheKey());
            }
            catch
            {
                // if an exception is thrown we need to remove the entry from cache,
                // this is ONLY a work around because of the way
                // that we cache entities: http://issues.umbraco.org/issue/U4-4259
-                Cache.ClearCacheItem(GetEntityCacheKey(entity.Id));
+                Cache.Clear(GetEntityCacheKey(entity.Id));

                // if there's a GetAllCacheAllowZeroCount cache, ensure it is cleared
-                Cache.ClearCacheItem(GetEntityTypeCacheKey());
+                Cache.Clear(GetEntityTypeCacheKey());

                throw;
            }
@@ -142,9 +142,9 @@ namespace Umbraco.Core.Cache
            {
                // whatever happens, clear the cache
                var cacheKey = GetEntityCacheKey(entity.Id);
-                Cache.ClearCacheItem(cacheKey);
+                Cache.Clear(cacheKey);
                // if there's a GetAllCacheAllowZeroCount cache, ensure it is cleared
-                Cache.ClearCacheItem(GetEntityTypeCacheKey());
+                Cache.Clear(GetEntityTypeCacheKey());
            }
        }

@@ -238,7 +238,7 @@ namespace Umbraco.Core.Cache
        /// <inheritdoc />
        public override void ClearAll()
        {
-            Cache.ClearCacheByKeySearch(GetEntityTypeCacheKey());
+            Cache.ClearByKey(GetEntityTypeCacheKey());
        }
    }
 }
@@ -0,0 +1,96 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Text.RegularExpressions;
+
+namespace Umbraco.Core.Cache
+{
+    /// <summary>
+    /// Implements <see cref="IAppCache"/> on top of a concurrent dictionary.
+    /// </summary>
+    public class DictionaryAppCache : IAppCache
+    {
+        /// <summary>
+        /// Gets the internal items dictionary, for tests only!
+        /// </summary>
+        internal readonly ConcurrentDictionary<string, object> Items = new ConcurrentDictionary<string, object>();
+
+        /// <inheritdoc />
+        public virtual object Get(string key)
+        {
+            return Items.TryGetValue(key, out var value) ? value : null;
+        }
+
+        /// <inheritdoc />
+        public virtual object Get(string key, Func<object> factory)
+        {
+            return Items.GetOrAdd(key, _ => factory());
+        }
+
+        /// <inheritdoc />
+        public virtual IEnumerable<object> SearchByKey(string keyStartsWith)
+        {
+            var items = new List<object>();
+            foreach (var (key, value) in Items)
+                if (key.InvariantStartsWith(keyStartsWith))
+                    items.Add(value);
+            return items;
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<object> SearchByRegex(string regex)
+        {
+            var compiled = new Regex(regex, RegexOptions.Compiled);
+            var items = new List<object>();
+            foreach (var (key, value) in Items)
+                if (compiled.IsMatch(key))
+                    items.Add(value);
+            return items;
+        }
+
+        /// <inheritdoc />
+        public virtual void Clear()
+        {
+            Items.Clear();
+        }
+
+        /// <inheritdoc />
+        public virtual void Clear(string key)
+        {
+            Items.TryRemove(key, out _);
+        }
+
+        /// <inheritdoc />
+        public virtual void ClearOfType(string typeName)
+        {
+            Items.RemoveAll(kvp => kvp.Value != null && kvp.Value.GetType().ToString().InvariantEquals(typeName));
+        }
+
+        /// <inheritdoc />
+        public virtual void ClearOfType<T>()
+        {
+            var typeOfT = typeof(T);
+            Items.RemoveAll(kvp => kvp.Value != null && kvp.Value.GetType() == typeOfT);
+        }
+
+        /// <inheritdoc />
+        public virtual void ClearOfType<T>(Func<string, T, bool> predicate)
+        {
+            var typeOfT = typeof(T);
+            Items.RemoveAll(kvp => kvp.Value != null && kvp.Value.GetType() == typeOfT && predicate(kvp.Key, (T)kvp.Value));
+        }
+
+        /// <inheritdoc />
+        public virtual void ClearByKey(string keyStartsWith)
+        {
+            Items.RemoveAll(kvp => kvp.Key.InvariantStartsWith(keyStartsWith));
+        }
+
+        /// <inheritdoc />
+        public virtual void ClearByRegex(string regex)
+        {
+            var compiled = new Regex(regex, RegexOptions.Compiled);
+            Items.RemoveAll(kvp => compiled.IsMatch(kvp.Key));
+        }
+    }
+}
@@ -7,79 +7,130 @@ using Umbraco.Core.Composing;

 namespace Umbraco.Core.Cache
 {
-    internal class DictionaryCacheProvider : ICacheProvider
+    /// <summary>
+    /// Implements a fast <see cref="IAppCache"/> on top of a concurrent dictionary.
+    /// </summary>
+    internal class FastDictionaryAppCache : IAppCache
    {
-        private readonly ConcurrentDictionary<string, Lazy<object>> _items
-            = new ConcurrentDictionary<string, Lazy<object>>();
+        /// <summary>
+        /// Gets the internal items dictionary, for tests only!
+        /// </summary>
+        internal readonly ConcurrentDictionary<string, Lazy<object>> Items = new ConcurrentDictionary<string, Lazy<object>>();

-        // for tests
-        internal ConcurrentDictionary<string, Lazy<object>> Items => _items;
-
-        public void ClearAllCache()
+        /// <inheritdoc />
+        public object Get(string cacheKey)
        {
-            _items.Clear();
+            Items.TryGetValue(cacheKey, out var result); // else null
+            return result == null ? null : FastDictionaryAppCacheBase.GetSafeLazyValue(result); // return exceptions as null
        }

-        public void ClearCacheItem(string key)
+        /// <inheritdoc />
+        public object Get(string cacheKey, Func<object> getCacheItem)
        {
-            _items.TryRemove(key, out _);
+            var result = Items.GetOrAdd(cacheKey, k => FastDictionaryAppCacheBase.GetSafeLazy(getCacheItem));
+
+            var value = result.Value; // will not throw (safe lazy)
+            if (!(value is FastDictionaryAppCacheBase.ExceptionHolder eh))
+                return value;
+
+            // and... it's in the cache anyway - so contrary to other cache providers,
+            // which would trick with GetSafeLazyValue, we need to remove by ourselves,
+            // in order NOT to cache exceptions
+
+            Items.TryRemove(cacheKey, out result);
+            eh.Exception.Throw(); // throw once!
+            return null; // never reached
        }

-        public void ClearCacheObjectTypes(string typeName)
+        /// <inheritdoc />
+        public IEnumerable<object> SearchByKey(string keyStartsWith)
+        {
+            return Items
+                .Where(kvp => kvp.Key.InvariantStartsWith(keyStartsWith))
+                .Select(kvp => FastDictionaryAppCacheBase.GetSafeLazyValue(kvp.Value))
+                .Where(x => x != null);
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<object> SearchByRegex(string regex)
+        {
+            var compiled = new Regex(regex, RegexOptions.Compiled);
+            return Items
+                .Where(kvp => compiled.IsMatch(kvp.Key))
+                .Select(kvp => FastDictionaryAppCacheBase.GetSafeLazyValue(kvp.Value))
+                .Where(x => x != null);
+        }
+
+        /// <inheritdoc />
+        public void Clear()
+        {
+            Items.Clear();
+        }
+
+        /// <inheritdoc />
+        public void Clear(string key)
+        {
+            Items.TryRemove(key, out _);
+        }
+
+        /// <inheritdoc />
+        public void ClearOfType(string typeName)
        {
            var type = TypeFinder.GetTypeByName(typeName);
            if (type == null) return;
            var isInterface = type.IsInterface;

-            foreach (var kvp in _items
+            foreach (var kvp in Items
                .Where(x =>
                {
                    // entry.Value is Lazy<object> and not null, its value may be null
                    // remove null values as well, does not hurt
                    // get non-created as NonCreatedValue & exceptions as null
-                    var value = DictionaryCacheProviderBase.GetSafeLazyValue(x.Value, true);
+                    var value = FastDictionaryAppCacheBase.GetSafeLazyValue(x.Value, true);

                    // if T is an interface remove anything that implements that interface
                    // otherwise remove exact types (not inherited types)
                    return value == null || (isInterface ? (type.IsInstanceOfType(value)) : (value.GetType() == type));
                }))
-                _items.TryRemove(kvp.Key, out _);
+                Items.TryRemove(kvp.Key, out _);
        }

-        public void ClearCacheObjectTypes<T>()
+        /// <inheritdoc />
+        public void ClearOfType<T>()
        {
            var typeOfT = typeof(T);
            var isInterface = typeOfT.IsInterface;

-            foreach (var kvp in _items
+            foreach (var kvp in Items
                .Where(x =>
                {
                    // entry.Value is Lazy<object> and not null, its value may be null
                    // remove null values as well, does not hurt
                    // compare on exact type, don't use "is"
                    // get non-created as NonCreatedValue & exceptions as null
-                    var value = DictionaryCacheProviderBase.GetSafeLazyValue(x.Value, true);
+                    var value = FastDictionaryAppCacheBase.GetSafeLazyValue(x.Value, true);

                    // if T is an interface remove anything that implements that interface
                    // otherwise remove exact types (not inherited types)
                    return value == null || (isInterface ? (value is T) : (value.GetType() == typeOfT));
                }))
-                _items.TryRemove(kvp.Key, out _);
+                Items.TryRemove(kvp.Key, out _);
        }

-        public void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate)
+        /// <inheritdoc />
+        public void ClearOfType<T>(Func<string, T, bool> predicate)
        {
            var typeOfT = typeof(T);
            var isInterface = typeOfT.IsInterface;

-            foreach (var kvp in _items
+            foreach (var kvp in Items
                .Where(x =>
                {
                    // entry.Value is Lazy<object> and not null, its value may be null
                    // remove null values as well, does not hurt
                    // compare on exact type, don't use "is"
                    // get non-created as NonCreatedValue & exceptions as null
-                    var value = DictionaryCacheProviderBase.GetSafeLazyValue(x.Value, true);
+                    var value = FastDictionaryAppCacheBase.GetSafeLazyValue(x.Value, true);
                    if (value == null) return true;

                    // if T is an interface remove anything that implements that interface
@@ -88,60 +139,24 @@ namespace Umbraco.Core.Cache
                            // run predicate on the 'public key' part only, ie without prefix
                            && predicate(x.Key, (T)value);
                }))
-                _items.TryRemove(kvp.Key, out _);
+                Items.TryRemove(kvp.Key, out _);
        }

-        public void ClearCacheByKeySearch(string keyStartsWith)
+        /// <inheritdoc />
+        public void ClearByKey(string keyStartsWith)
        {
-            foreach (var ikvp in _items
+            foreach (var ikvp in Items
                .Where(kvp => kvp.Key.InvariantStartsWith(keyStartsWith)))
-                _items.TryRemove(ikvp.Key, out _);
+                Items.TryRemove(ikvp.Key, out _);
        }

-        public void ClearCacheByKeyExpression(string regexString)
+        /// <inheritdoc />
+        public void ClearByRegex(string regex)
        {
-            foreach (var ikvp in _items
-                .Where(kvp => Regex.IsMatch(kvp.Key, regexString)))
-                _items.TryRemove(ikvp.Key, out _);
-        }
-
-        public IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith)
-        {
-            return _items
-                .Where(kvp => kvp.Key.InvariantStartsWith(keyStartsWith))
-                .Select(kvp => DictionaryCacheProviderBase.GetSafeLazyValue(kvp.Value))
-                .Where(x => x != null);
-        }
-
-        public IEnumerable<object> GetCacheItemsByKeyExpression(string regexString)
-        {
-            return _items
-                .Where(kvp => Regex.IsMatch(kvp.Key, regexString))
-                .Select(kvp => DictionaryCacheProviderBase.GetSafeLazyValue(kvp.Value))
-                .Where(x => x != null);
-        }
-
-        public object GetCacheItem(string cacheKey)
-        {
-            _items.TryGetValue(cacheKey, out var result); // else null
-            return result == null ? null : DictionaryCacheProviderBase.GetSafeLazyValue(result); // return exceptions as null
-        }
-
-        public object GetCacheItem(string cacheKey, Func<object> getCacheItem)
-        {
-            var result = _items.GetOrAdd(cacheKey, k => DictionaryCacheProviderBase.GetSafeLazy(getCacheItem));
-
-            var value = result.Value; // will not throw (safe lazy)
-            if (!(value is DictionaryCacheProviderBase.ExceptionHolder eh))
-                return value;
-
-            // and... it's in the cache anyway - so contrary to other cache providers,
-            // which would trick with GetSafeLazyValue, we need to remove by ourselves,
-            // in order NOT to cache exceptions
-
-            _items.TryRemove(cacheKey, out result);
-            eh.Exception.Throw(); // throw once!
-            return null; // never reached
+            var compiled = new Regex(regex, RegexOptions.Compiled);
+            foreach (var ikvp in Items
+                .Where(kvp => compiled.IsMatch(kvp.Key)))
+                Items.TryRemove(ikvp.Key, out _);
        }
    }
 }
@@ -8,7 +8,10 @@ using Umbraco.Core.Composing;

 namespace Umbraco.Core.Cache
 {
-    internal abstract class DictionaryCacheProviderBase : ICacheProvider
+    /// <summary>
+    /// Provides a base class to fast, dictionary-based <see cref="IAppCache"/> implementations.
+    /// </summary>
+    internal abstract class FastDictionaryAppCacheBase : IAppCache
    {
        // prefix cache keys so we know which one are ours
        protected const string CacheItemPrefix = "umbrtmche";
@@ -16,82 +19,75 @@ namespace Umbraco.Core.Cache
        // an object that represent a value that has not been created yet
        protected internal static readonly object ValueNotCreated = new object();

-        // manupulate the underlying cache entries
-        // these *must* be called from within the appropriate locks
-        // and use the full prefixed cache keys
-        protected abstract IEnumerable<DictionaryEntry> GetDictionaryEntries();
-        protected abstract void RemoveEntry(string key);
-        protected abstract object GetEntry(string key);
+        #region IAppCache

-        // read-write lock the underlying cache
-        //protected abstract IDisposable ReadLock { get; }
-        //protected abstract IDisposable WriteLock { get; }
-
-        protected abstract void EnterReadLock();
-        protected abstract void ExitReadLock();
-        protected abstract void EnterWriteLock();
-        protected abstract void ExitWriteLock();
-
-        protected string GetCacheKey(string key)
+        /// <inheritdoc />
+        public virtual object Get(string key)
        {
-            return string.Format("{0}-{1}", CacheItemPrefix, key);
-        }
-
-        protected internal static Lazy<object> GetSafeLazy(Func<object> getCacheItem)
-        {
-            // try to generate the value and if it fails,
-            // wrap in an ExceptionHolder - would be much simpler
-            // to just use lazy.IsValueFaulted alas that field is
-            // internal
-            return new Lazy<object>(() =>
-            {
-                try
-                {
-                    return getCacheItem();
-                }
-                catch (Exception e)
-                {
-                    return new ExceptionHolder(ExceptionDispatchInfo.Capture(e));
-                }
-            });
-        }
-
-        protected internal static object GetSafeLazyValue(Lazy<object> lazy, bool onlyIfValueIsCreated = false)
-        {
-            // if onlyIfValueIsCreated, do not trigger value creation
-            // must return something, though, to differenciate from null values
-            if (onlyIfValueIsCreated && lazy.IsValueCreated == false) return ValueNotCreated;
-
-            // if execution has thrown then lazy.IsValueCreated is false
-            // and lazy.IsValueFaulted is true (but internal) so we use our
-            // own exception holder (see Lazy<T> source code) to return null
-            if (lazy.Value is ExceptionHolder) return null;
-
-            // we have a value and execution has not thrown so returning
-            // here does not throw - unless we're re-entering, take care of it
+            key = GetCacheKey(key);
+            Lazy<object> result;
            try
            {
-                return lazy.Value;
+                EnterReadLock();
+                result = GetEntry(key) as Lazy<object>; // null if key not found
            }
-            catch (InvalidOperationException e)
+            finally
            {
-                throw new InvalidOperationException("The method that computes a value for the cache has tried to read that value from the cache.", e);
+                ExitReadLock();
            }
+            return result == null ? null : GetSafeLazyValue(result); // return exceptions as null
        }

-        internal class ExceptionHolder
+        /// <inheritdoc />
+        public abstract object Get(string key, Func<object> factory);
+
+        /// <inheritdoc />
+        public virtual IEnumerable<object> SearchByKey(string keyStartsWith)
        {
-            public ExceptionHolder(ExceptionDispatchInfo e)
+            var plen = CacheItemPrefix.Length + 1;
+            IEnumerable<DictionaryEntry> entries;
+            try
            {
-                Exception = e;
+                EnterReadLock();
+                entries = GetDictionaryEntries()
+                    .Where(x => ((string)x.Key).Substring(plen).InvariantStartsWith(keyStartsWith))
+                    .ToArray(); // evaluate while locked
+            }
+            finally
+            {
+                ExitReadLock();
            }

-            public ExceptionDispatchInfo Exception { get; }
+            return entries
+                .Select(x => GetSafeLazyValue((Lazy<object>)x.Value)) // return exceptions as null
+                .Where(x => x != null); // backward compat, don't store null values in the cache
        }

-        #region Clear
+        /// <inheritdoc />
+        public virtual IEnumerable<object> SearchByRegex(string regex)
+        {
+            const string prefix = CacheItemPrefix + "-";
+            var compiled = new Regex(regex, RegexOptions.Compiled);
+            var plen = prefix.Length;
+            IEnumerable<DictionaryEntry> entries;
+            try
+            {
+                EnterReadLock();
+                entries = GetDictionaryEntries()
+                    .Where(x => compiled.IsMatch(((string)x.Key).Substring(plen)))
+                    .ToArray(); // evaluate while locked
+            }
+            finally
+            {
+                ExitReadLock();
+            }
+            return entries
+                .Select(x => GetSafeLazyValue((Lazy<object>)x.Value)) // return exceptions as null
+                .Where(x => x != null); // backward compatible, don't store null values in the cache
+        }

-        public virtual void ClearAllCache()
+        /// <inheritdoc />
+        public virtual void Clear()
        {
            try
            {
@@ -106,7 +102,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheItem(string key)
+        /// <inheritdoc />
+        public virtual void Clear(string key)
        {
            var cacheKey = GetCacheKey(key);
            try
@@ -120,7 +117,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheObjectTypes(string typeName)
+        /// <inheritdoc />
+        public virtual void ClearOfType(string typeName)
        {
            var type = TypeFinder.GetTypeByName(typeName);
            if (type == null) return;
@@ -149,7 +147,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheObjectTypes<T>()
+        /// <inheritdoc />
+        public virtual void ClearOfType<T>()
        {
            var typeOfT = typeof(T);
            var isInterface = typeOfT.IsInterface;
@@ -178,7 +177,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate)
+        /// <inheritdoc />
+        public virtual void ClearOfType<T>(Func<string, T, bool> predicate)
        {
            var typeOfT = typeof(T);
            var isInterface = typeOfT.IsInterface;
@@ -210,7 +210,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheByKeySearch(string keyStartsWith)
+        /// <inheritdoc />
+        public virtual void ClearByKey(string keyStartsWith)
        {
            var plen = CacheItemPrefix.Length + 1;
            try
@@ -227,14 +228,16 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheByKeyExpression(string regexString)
+        /// <inheritdoc />
+        public virtual void ClearByRegex(string regex)
        {
+            var compiled = new Regex(regex, RegexOptions.Compiled);
            var plen = CacheItemPrefix.Length + 1;
            try
            {
                EnterWriteLock();
                foreach (var entry in GetDictionaryEntries()
-                    .Where(x => Regex.IsMatch(((string)x.Key).Substring(plen), regexString))
+                    .Where(x => compiled.IsMatch(((string)x.Key).Substring(plen)))
                    .ToArray())
                    RemoveEntry((string) entry.Key);
            }
@@ -246,67 +249,80 @@ namespace Umbraco.Core.Cache

        #endregion

-        #region Get
+        #region Dictionary

-        public virtual IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith)
+        // manipulate the underlying cache entries
+        // these *must* be called from within the appropriate locks
+        // and use the full prefixed cache keys
+        protected abstract IEnumerable<DictionaryEntry> GetDictionaryEntries();
+        protected abstract void RemoveEntry(string key);
+        protected abstract object GetEntry(string key);
+
+        // read-write lock the underlying cache
+        //protected abstract IDisposable ReadLock { get; }
+        //protected abstract IDisposable WriteLock { get; }
+
+        protected abstract void EnterReadLock();
+        protected abstract void ExitReadLock();
+        protected abstract void EnterWriteLock();
+        protected abstract void ExitWriteLock();
+
+        protected string GetCacheKey(string key)
        {
-            var plen = CacheItemPrefix.Length + 1;
-            IEnumerable<DictionaryEntry> entries;
-            try
-            {
-                EnterReadLock();
-                entries = GetDictionaryEntries()
-                    .Where(x => ((string)x.Key).Substring(plen).InvariantStartsWith(keyStartsWith))
-                    .ToArray(); // evaluate while locked
-            }
-            finally
-            {
-                ExitReadLock();
-            }
-
-            return entries
-                    .Select(x => GetSafeLazyValue((Lazy<object>)x.Value)) // return exceptions as null
-                    .Where(x => x != null); // backward compat, don't store null values in the cache
+            return $"{CacheItemPrefix}-{key}";
        }

-        public virtual IEnumerable<object> GetCacheItemsByKeyExpression(string regexString)
+        protected internal static Lazy<object> GetSafeLazy(Func<object> getCacheItem)
        {
-            const string prefix = CacheItemPrefix + "-";
-            var plen = prefix.Length;
-            IEnumerable<DictionaryEntry> entries;
-            try
+            // try to generate the value and if it fails,
+            // wrap in an ExceptionHolder - would be much simpler
+            // to just use lazy.IsValueFaulted alas that field is
+            // internal
+            return new Lazy<object>(() =>
            {
-                EnterReadLock();
-                entries = GetDictionaryEntries()
-                    .Where(x => Regex.IsMatch(((string)x.Key).Substring(plen), regexString))
-                    .ToArray(); // evaluate while locked
-            }
-            finally
-            {
-                ExitReadLock();
-            }
-            return entries
-                    .Select(x => GetSafeLazyValue((Lazy<object>)x.Value)) // return exceptions as null
-                    .Where(x => x != null); // backward compat, don't store null values in the cache
+                try
+                {
+                    return getCacheItem();
+                }
+                catch (Exception e)
+                {
+                    return new ExceptionHolder(ExceptionDispatchInfo.Capture(e));
+                }
+            });
        }

-        public virtual object GetCacheItem(string cacheKey)
+        protected internal static object GetSafeLazyValue(Lazy<object> lazy, bool onlyIfValueIsCreated = false)
        {
-            cacheKey = GetCacheKey(cacheKey);
-            Lazy<object> result;
+            // if onlyIfValueIsCreated, do not trigger value creation
+            // must return something, though, to differentiate from null values
+            if (onlyIfValueIsCreated && lazy.IsValueCreated == false) return ValueNotCreated;
+
+            // if execution has thrown then lazy.IsValueCreated is false
+            // and lazy.IsValueFaulted is true (but internal) so we use our
+            // own exception holder (see Lazy<T> source code) to return null
+            if (lazy.Value is ExceptionHolder) return null;
+
+            // we have a value and execution has not thrown so returning
+            // here does not throw - unless we're re-entering, take care of it
            try
            {
-                EnterReadLock();
-                result = GetEntry(cacheKey) as Lazy<object>; // null if key not found
+                return lazy.Value;
            }
-            finally
+            catch (InvalidOperationException e)
            {
-                ExitReadLock();
+                throw new InvalidOperationException("The method that computes a value for the cache has tried to read that value from the cache.", e);
            }
-            return result == null ? null : GetSafeLazyValue(result); // return exceptions as null
        }

-        public abstract object GetCacheItem(string cacheKey, Func<object> getCacheItem);
+        internal class ExceptionHolder
+        {
+            public ExceptionHolder(ExceptionDispatchInfo e)
+            {
+                Exception = e;
+            }
+
+            public ExceptionDispatchInfo Exception { get; }
+        }

        #endregion
    }
@@ -24,7 +24,7 @@ namespace Umbraco.Core.Cache
        private readonly Func<TEntity, TId> _entityGetId;
        private readonly bool _expires;

-        public FullDataSetRepositoryCachePolicy(IRuntimeCacheProvider cache, IScopeAccessor scopeAccessor, Func<TEntity, TId> entityGetId, bool expires)
+        public FullDataSetRepositoryCachePolicy(IAppPolicyCache cache, IScopeAccessor scopeAccessor, Func<TEntity, TId> entityGetId, bool expires)
            : base(cache, scopeAccessor)
        {
            _entityGetId = entityGetId;
@@ -55,11 +55,11 @@ namespace Umbraco.Core.Cache

            if (_expires)
            {
-                Cache.InsertCacheItem(key, () => new DeepCloneableList<TEntity>(entities), TimeSpan.FromMinutes(5), true);
+                Cache.Insert(key, () => new DeepCloneableList<TEntity>(entities), TimeSpan.FromMinutes(5), true);
            }
            else
            {
-                Cache.InsertCacheItem(key, () => new DeepCloneableList<TEntity>(entities));
+                Cache.Insert(key, () => new DeepCloneableList<TEntity>(entities));
            }
        }

@@ -171,7 +171,7 @@ namespace Umbraco.Core.Cache
        /// <inheritdoc />
        public override void ClearAll()
        {
-            Cache.ClearCacheItem(GetEntityTypeCacheKey());
+            Cache.Clear(GetEntityTypeCacheKey());
        }
    }
 }
@@ -7,54 +7,83 @@ using System.Web;
 namespace Umbraco.Core.Cache
 {
    /// <summary>
-    /// A cache provider that caches items in the HttpContext.Items
+    /// Implements a fast <see cref="IAppCache"/> on top of HttpContext.Items.
    /// </summary>
    /// <remarks>
-    /// If the Items collection is null, then this provider has no effect
+    /// <para>If no current HttpContext items can be found (no current HttpContext,
+    /// or no Items...) then this cache acts as a pass-through and does not cache
+    /// anything.</para>
    /// </remarks>
-    internal class HttpRequestCacheProvider : DictionaryCacheProviderBase
+    internal class HttpRequestAppCache : FastDictionaryAppCacheBase
    {
-        // context provider
-        // the idea is that there is only one, application-wide HttpRequestCacheProvider instance,
-        // that is initialized with a method that returns the "current" context.
-        // NOTE
-        //   but then it is initialized with () => new HttpContextWrapper(HttpContent.Current)
-        //   which is higly inefficient because it creates a new wrapper each time we refer to _context()
-        //   so replace it with _context1 and _context2 below + a way to get context.Items.
-        //private readonly Func<HttpContextBase> _context;
-
-        // NOTE
-        //   and then in almost 100% cases _context2 will be () => HttpContext.Current
-        //   so why not bring that logic in here and fallback on to HttpContext.Current when
-        //   _context1 is null?
-        //private readonly HttpContextBase _context1;
-        //private readonly Func<HttpContext> _context2;
        private readonly HttpContextBase _context;

-        private IDictionary ContextItems
-        {
-            //get { return _context1 != null ? _context1.Items : _context2().Items; }
-            get { return _context != null ? _context.Items : HttpContext.Current.Items; }
-        }
-
-        private bool HasContextItems
-        {
-            get { return (_context != null && _context.Items != null) || HttpContext.Current != null; }
-        }
-
-        // for unit tests
-        public HttpRequestCacheProvider(HttpContextBase context)
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpRequestAppCache"/> class with a context, for unit tests!
+        /// </summary>
+        public HttpRequestAppCache(HttpContextBase context)
        {
            _context = context;
        }

-        // main constructor
-        // will use HttpContext.Current
-        public HttpRequestCacheProvider(/*Func<HttpContext> context*/)
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HttpRequestAppCache"/> class.
+        /// </summary>
+        /// <remarks>
+        /// <para>Will use HttpContext.Current.</para>
+        /// TODO: https://github.com/umbraco/Umbraco-CMS/issues/4239 - use IHttpContextAccessor NOT HttpContext.Current
+        /// </remarks>
+        public HttpRequestAppCache()
+        { }
+
+        private IDictionary ContextItems => _context?.Items ?? HttpContext.Current?.Items;
+
+        private bool HasContextItems => _context?.Items != null || HttpContext.Current != null;
+
+        /// <inheritdoc />
+        public override object Get(string key, Func<object> factory)
        {
-            //_context2 = context;
+            //no place to cache so just return the callback result
+            if (HasContextItems == false) return factory();
+
+            key = GetCacheKey(key);
+
+            Lazy<object> result;
+
+            try
+            {
+                EnterWriteLock();
+                result = ContextItems[key] as Lazy<object>; // null if key not found
+
+                // cannot create value within the lock, so if result.IsValueCreated is false, just
+                // do nothing here - means that if creation throws, a race condition could cause
+                // more than one thread to reach the return statement below and throw - accepted.
+
+                if (result == null || GetSafeLazyValue(result, true) == null) // get non-created as NonCreatedValue & exceptions as null
+                {
+                    result = GetSafeLazy(factory);
+                    ContextItems[key] = result;
+                }
+            }
+            finally
+            {
+                ExitWriteLock();
+            }
+
+            // using GetSafeLazy and GetSafeLazyValue ensures that we don't cache
+            // exceptions (but try again and again) and silently eat them - however at
+            // some point we have to report them - so need to re-throw here
+
+            // this does not throw anymore
+            //return result.Value;
+
+            var value = result.Value; // will not throw (safe lazy)
+            if (value is ExceptionHolder eh) eh.Exception.Throw(); // throw once!
+            return value;
        }

+        #region Entries
+
        protected override IEnumerable<DictionaryEntry> GetDictionaryEntries()
        {
            const string prefix = CacheItemPrefix + "-";
@@ -62,7 +91,7 @@ namespace Umbraco.Core.Cache
            if (HasContextItems == false) return Enumerable.Empty<DictionaryEntry>();

            return ContextItems.Cast<DictionaryEntry>()
-                .Where(x => x.Key is string && ((string)x.Key).StartsWith(prefix));
+                .Where(x => x.Key is string s && s.StartsWith(prefix));
        }

        protected override void RemoveEntry(string key)
@@ -77,6 +106,8 @@ namespace Umbraco.Core.Cache
            return HasContextItems ? ContextItems[key] : null;
        }

+        #endregion
+
        #region Lock

        private bool _entered;
@@ -103,59 +134,5 @@ namespace Umbraco.Core.Cache
        }

        #endregion
-
-        #region Get
-
-        public override object GetCacheItem(string cacheKey, Func<object> getCacheItem)
-        {
-            //no place to cache so just return the callback result
-            if (HasContextItems == false) return getCacheItem();
-
-            cacheKey = GetCacheKey(cacheKey);
-
-            Lazy<object> result;
-
-            try
-            {
-                EnterWriteLock();
-                result = ContextItems[cacheKey] as Lazy<object>; // null if key not found
-
-                // cannot create value within the lock, so if result.IsValueCreated is false, just
-                // do nothing here - means that if creation throws, a race condition could cause
-                // more than one thread to reach the return statement below and throw - accepted.
-
-                if (result == null || GetSafeLazyValue(result, true) == null) // get non-created as NonCreatedValue & exceptions as null
-                {
-                    result = GetSafeLazy(getCacheItem);
-                    ContextItems[cacheKey] = result;
-                }
-            }
-            finally
-            {
-                ExitWriteLock();
-            }
-
-            // using GetSafeLazy and GetSafeLazyValue ensures that we don't cache
-            // exceptions (but try again and again) and silently eat them - however at
-            // some point we have to report them - so need to re-throw here
-
-            // this does not throw anymore
-            //return result.Value;
-
-            var value = result.Value; // will not throw (safe lazy)
-            if (value is ExceptionHolder eh) eh.Exception.Throw(); // throw once!
-            return value;
-        }
-
-        #endregion
-
-        #region Insert
-        #endregion
-
-        private class NoopLocker : DisposableObjectSlim
-        {
-            protected override void DisposeResources()
-            { }
-        }
    }
 }
@@ -0,0 +1,94 @@
+using System;
+using System.Collections.Generic;
+
+namespace Umbraco.Core.Cache
+{
+    /// <summary>
+    /// Defines an application cache.
+    /// </summary>
+    public interface IAppCache
+    {
+        /// <summary>
+        /// Gets an item identified by its key.
+        /// </summary>
+        /// <param name="key">The key of the item.</param>
+        /// <returns>The item, or null if the item was not found.</returns>
+        object Get(string key);
+
+        /// <summary>
+        /// Gets or creates an item identified by its key.
+        /// </summary>
+        /// <param name="key">The key of the item.</param>
+        /// <param name="factory">A factory function that can create the item.</param>
+        /// <returns>The item.</returns>
+        object Get(string key, Func<object> factory);
+
+        /// <summary>
+        /// Gets items with a key starting with the specified value.
+        /// </summary>
+        /// <param name="keyStartsWith">The StartsWith value to use in the search.</param>
+        /// <returns>Items matching the search.</returns>
+        IEnumerable<object> SearchByKey(string keyStartsWith);
+
+        /// <summary>
+        /// Gets items with a key matching a regular expression.
+        /// </summary>
+        /// <param name="regex">The regular expression.</param>
+        /// <returns>Items matching the search.</returns>
+        IEnumerable<object> SearchByRegex(string regex);
+
+        /// <summary>
+        /// Removes all items from the cache.
+        /// </summary>
+        void Clear();
+
+        /// <summary>
+        /// Removes an item identified by its key from the cache.
+        /// </summary>
+        /// <param name="key">The key of the item.</param>
+        void Clear(string key);
+
+        /// <summary>
+        /// Removes items of a specified type from the cache.
+        /// </summary>
+        /// <param name="typeName">The name of the type to remove.</param>
+        /// <remarks>
+        /// <para>If the type is an interface, then all items of a type implementing that interface are
+        /// removed. Otherwise, only items of that exact type are removed (items of type inheriting from
+        /// the specified type are not removed).</para>
+        /// <para>Performs a case-sensitive search.</para>
+        /// </remarks>
+        void ClearOfType(string typeName);
+
+        /// <summary>
+        /// Removes items of a specified type from the cache.
+        /// </summary>
+        /// <typeparam name="T">The type of the items to remove.</typeparam>
+        /// <remarks>If the type is an interface, then all items of a type implementing that interface are
+        /// removed. Otherwise, only items of that exact type are removed (items of type inheriting from
+        /// the specified type are not removed).</remarks>
+        void ClearOfType<T>();
+
+        /// <summary>
+        /// Removes items of a specified type from the cache.
+        /// </summary>
+        /// <typeparam name="T">The type of the items to remove.</typeparam>
+        /// <param name="predicate">The predicate to satisfy.</param>
+        /// <remarks>If the type is an interface, then all items of a type implementing that interface are
+        /// removed. Otherwise, only items of that exact type are removed (items of type inheriting from
+        /// the specified type are not removed).</remarks>
+        void ClearOfType<T>(Func<string, T, bool> predicate);
+
+        /// <summary>
+        /// Clears items with a key starting with the specified value.
+        /// </summary>
+        /// <param name="keyStartsWith">The StartsWith value to use in the search.</param>
+        void ClearByKey(string keyStartsWith);
+
+        /// <summary>
+        /// Clears items with a key matching a regular expression.
+        /// </summary>
+        /// <param name="regex">The regular expression.</param>
+        void ClearByRegex(string regex);
+    }
+}
@@ -0,0 +1,52 @@
+using System;
+using System.Web.Caching;
+
+namespace Umbraco.Core.Cache
+{
+    /// <summary>
+    /// Defines an application cache that support cache policies.
+    /// </summary>
+    /// <remarks>A cache policy can be used to cache with timeouts,
+    /// or depending on files, and with a remove callback, etc.</remarks>
+    public interface IAppPolicyCache : IAppCache
+    {
+        /// <summary>
+        /// Gets an item identified by its key.
+        /// </summary>
+        /// <param name="key">The key of the item.</param>
+        /// <param name="factory">A factory function that can create the item.</param>
+        /// <param name="timeout">An optional cache timeout.</param>
+        /// <param name="isSliding">An optional value indicating whether the cache timeout is sliding (default is false).</param>
+        /// <param name="priority">An optional cache priority (default is Normal).</param>
+        /// <param name="removedCallback">An optional callback to handle removals.</param>
+        /// <param name="dependentFiles">Files the cache entry depends on.</param>
+        /// <returns>The item.</returns>
+        object Get(
+            string key,
+            Func<object> factory,
+            TimeSpan? timeout,
+            bool isSliding = false,
+            CacheItemPriority priority = CacheItemPriority.Normal,
+            CacheItemRemovedCallback removedCallback = null,
+            string[] dependentFiles = null);
+
+        /// <summary>
+        /// Inserts an item.
+        /// </summary>
+        /// <param name="key">The key of the item.</param>
+        /// <param name="factory">A factory function that can create the item.</param>
+        /// <param name="timeout">An optional cache timeout.</param>
+        /// <param name="isSliding">An optional value indicating whether the cache timeout is sliding (default is false).</param>
+        /// <param name="priority">An optional cache priority (default is Normal).</param>
+        /// <param name="removedCallback">An optional callback to handle removals.</param>
+        /// <param name="dependentFiles">Files the cache entry depends on.</param>
+        void Insert(
+            string key,
+            Func<object> factory,
+            TimeSpan? timeout = null,
+            bool isSliding = false,
+            CacheItemPriority priority = CacheItemPriority.Normal,
+            CacheItemRemovedCallback removedCallback = null,
+            string[] dependentFiles = null);
+    }
+}
@@ -1,68 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-namespace Umbraco.Core.Cache
-{
-    /// <summary>
-    /// An interface for implementing a basic cache provider
-    /// </summary>
-    public interface ICacheProvider
-    {
-        /// <summary>
-        /// Removes all items from the cache.
-        /// </summary>
-        void ClearAllCache();
-
-        /// <summary>
-        /// Removes an item from the cache, identified by its key.
-        /// </summary>
-        /// <param name="key">The key of the item.</param>
-        void ClearCacheItem(string key);
-
-        /// <summary>
-        /// Removes items from the cache, of a specified type.
-        /// </summary>
-        /// <param name="typeName">The name of the type to remove.</param>
-        /// <remarks>
-        /// <para>If the type is an interface, then all items of a type implementing that interface are
-        /// removed. Otherwise, only items of that exact type are removed (items of type inheriting from
-        /// the specified type are not removed).</para>
-        /// <para>Performs a case-sensitive search.</para>
-        /// </remarks>
-        void ClearCacheObjectTypes(string typeName);
-
-        /// <summary>
-        /// Removes items from the cache, of a specified type.
-        /// </summary>
-        /// <typeparam name="T">The type of the items to remove.</typeparam>
-        /// <remarks>If the type is an interface, then all items of a type implementing that interface are
-        /// removed. Otherwise, only items of that exact type are removed (items of type inheriting from
-        /// the specified type are not removed).</remarks>
-        void ClearCacheObjectTypes<T>();
-
-        /// <summary>
-        /// Removes items from the cache, of a specified type, satisfying a predicate.
-        /// </summary>
-        /// <typeparam name="T">The type of the items to remove.</typeparam>
-        /// <param name="predicate">The predicate to satisfy.</param>
-        /// <remarks>If the type is an interface, then all items of a type implementing that interface are
-        /// removed. Otherwise, only items of that exact type are removed (items of type inheriting from
-        /// the specified type are not removed).</remarks>
-        void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate);
-
-        void ClearCacheByKeySearch(string keyStartsWith);
-        void ClearCacheByKeyExpression(string regexString);
-
-        IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith);
-        IEnumerable<object> GetCacheItemsByKeyExpression(string regexString);
-
-        /// <summary>
-        /// Returns an item with a given key
-        /// </summary>
-        /// <param name="cacheKey"></param>
-        /// <returns></returns>
-        object GetCacheItem(string cacheKey);
-
-        object GetCacheItem(string cacheKey, Func<object> getCacheItem);
-    }
-}
@@ -4,7 +4,7 @@ using Umbraco.Core.Composing;
 namespace Umbraco.Core.Cache
 {
    /// <summary>
-    /// The IcacheRefresher Interface is used for loadbalancing.
+    /// The IcacheRefresher Interface is used for load balancing.
    ///
    /// </summary>
    public interface ICacheRefresher : IDiscoverable
@@ -48,7 +48,7 @@ namespace Umbraco.Core.Cache
        /// Updates an entity.
        /// </summary>
        /// <param name="entity">The entity.</param>
-        /// <param name="persistUpdated">The reopsitory PersistUpdatedItem method.</param>
+        /// <param name="persistUpdated">The repository PersistUpdatedItem method.</param>
        /// <remarks>Updates the entity in the repository, and updates the cache accordingly.</remarks>
        void Update(TEntity entity, Action<TEntity> persistUpdated);

@@ -1,35 +0,0 @@
-using System;
-using System.Runtime.Caching;
-using System.Text;
-using System.Web.Caching;
-using CacheItemPriority = System.Web.Caching.CacheItemPriority;
-
-namespace Umbraco.Core.Cache
-{
-    /// <summary>
-    /// An abstract class for implementing a runtime cache provider
-    /// </summary>
-    /// <remarks>
-    /// </remarks>
-    public interface IRuntimeCacheProvider : ICacheProvider
-    {
-        object GetCacheItem(
-            string cacheKey,
-            Func<object> getCacheItem,
-            TimeSpan? timeout,
-            bool isSliding = false,
-            CacheItemPriority priority = CacheItemPriority.Normal,
-            CacheItemRemovedCallback removedCallback = null,
-            string[] dependentFiles = null);
-
-        void InsertCacheItem(
-            string cacheKey,
-            Func<object> getCacheItem,
-            TimeSpan? timeout = null,
-            bool isSliding = false,
-            CacheItemPriority priority = CacheItemPriority.Normal,
-            CacheItemRemovedCallback removedCallback = null,
-            string[] dependentFiles = null);
-
-    }
-}
@@ -0,0 +1,41 @@
+using System;
+
+namespace Umbraco.Core.Cache
+{
+    /// <summary>
+    /// Represents a dictionary of <see cref="IAppPolicyCache"/> for types.
+    /// </summary>
+    /// <remarks>
+    /// <para>Isolated caches are used by e.g. repositories, to ensure that each cached entity
+    /// type has its own cache, so that lookups are fast and the repository does not need to
+    /// search through all keys on a global scale.</para>
+    /// </remarks>
+    public class IsolatedCaches : AppPolicedCacheDictionary<Type>
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="IsolatedCaches"/> class.
+        /// </summary>
+        /// <param name="cacheFactory"></param>
+        public IsolatedCaches(Func<Type, IAppPolicyCache> cacheFactory)
+            : base(cacheFactory)
+        { }
+
+        /// <summary>
+        /// Gets a cache.
+        /// </summary>
+        public IAppPolicyCache GetOrCreate<T>()
+            => GetOrCreate(typeof(T));
+
+        /// <summary>
+        /// Tries to get a cache.
+        /// </summary>
+        public Attempt<IAppPolicyCache> Get<T>()
+            => Get(typeof(T));
+
+        /// <summary>
+        /// Clears a cache.
+        /// </summary>
+        public void ClearCache<T>()
+            => ClearCache(typeof(T));
+    }
+}
@@ -1,91 +0,0 @@
-using System;
-using System.Collections.Concurrent;
-
-namespace Umbraco.Core.Cache
-{
-    /// <summary>
-    /// Used to get/create/manipulate isolated runtime cache
-    /// </summary>
-    /// <remarks>
-    /// This is useful for repository level caches to ensure that cache lookups by key are fast so
-    /// that the repository doesn't need to search through all keys on a global scale.
-    /// </remarks>
-    public class IsolatedRuntimeCache
-    {
-        internal Func<Type, IRuntimeCacheProvider> CacheFactory { get; set; }
-
-        /// <summary>
-        /// Constructor that allows specifying a factory for the type of runtime isolated cache to create
-        /// </summary>
-        /// <param name="cacheFactory"></param>
-        public IsolatedRuntimeCache(Func<Type, IRuntimeCacheProvider> cacheFactory)
-        {
-            CacheFactory = cacheFactory;
-        }
-
-        private readonly ConcurrentDictionary<Type, IRuntimeCacheProvider> _isolatedCache = new ConcurrentDictionary<Type, IRuntimeCacheProvider>();
-
-        /// <summary>
-        /// Returns an isolated runtime cache for a given type
-        /// </summary>
-        /// <typeparam name="T"></typeparam>
-        /// <returns></returns>
-        public IRuntimeCacheProvider GetOrCreateCache<T>()
-        {
-            return _isolatedCache.GetOrAdd(typeof(T), type => CacheFactory(type));
-        }
-
-        /// <summary>
-        /// Returns an isolated runtime cache for a given type
-        /// </summary>
-        /// <returns></returns>
-        public IRuntimeCacheProvider GetOrCreateCache(Type type)
-        {
-            return _isolatedCache.GetOrAdd(type, t => CacheFactory(t));
-        }
-
-        /// <summary>
-        /// Tries to get a cache by the type specified
-        /// </summary>
-        /// <typeparam name="T"></typeparam>
-        /// <returns></returns>
-        public Attempt<IRuntimeCacheProvider> GetCache<T>()
-        {
-            IRuntimeCacheProvider cache;
-            if (_isolatedCache.TryGetValue(typeof(T), out cache))
-            {
-                return Attempt.Succeed(cache);
-            }
-            return Attempt<IRuntimeCacheProvider>.Fail();
-        }
-
-        /// <summary>
-        /// Clears all values inside this isolated runtime cache
-        /// </summary>
-        /// <typeparam name="T"></typeparam>
-        /// <returns></returns>
-        public void ClearCache<T>()
-        {
-            IRuntimeCacheProvider cache;
-            if (_isolatedCache.TryGetValue(typeof(T), out cache))
-            {
-                cache.ClearAllCache();
-            }
-        }
-
-        /// <summary>
-        /// Clears all of the isolated caches
-        /// </summary>
-        public void ClearAllCaches()
-        {
-            foreach (var key in _isolatedCache.Keys)
-            {
-                IRuntimeCacheProvider cache;
-                if (_isolatedCache.TryRemove(key, out cache))
-                {
-                    cache.ClearAllCache();
-                }
-            }
-        }
-    }
-}
@@ -13,8 +13,8 @@ namespace Umbraco.Core.Cache
        /// <summary>
        /// Initializes a new instance of the <see cref="JsonCacheRefresherBase{TInstanceType}"/>.
        /// </summary>
-        /// <param name="cacheHelper">A cache helper.</param>
-        protected JsonCacheRefresherBase(CacheHelper cacheHelper) : base(cacheHelper)
+        /// <param name="appCaches">A cache helper.</param>
+        protected JsonCacheRefresherBase(AppCaches appCaches) : base(appCaches)
        { }

        /// <summary>
@@ -0,0 +1,82 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Web.Caching;
+
+namespace Umbraco.Core.Cache
+{
+    /// <summary>
+    /// Implements <see cref="IAppPolicyCache"/> and do not cache.
+    /// </summary>
+    public class NoAppCache : IAppPolicyCache
+    {
+        private NoAppCache() { }
+
+        /// <summary>
+        /// Gets the singleton instance.
+        /// </summary>
+        public static NoAppCache Instance { get; } = new NoAppCache();
+
+        /// <inheritdoc />
+        public virtual object Get(string cacheKey)
+        {
+            return null;
+        }
+
+        /// <inheritdoc />
+        public virtual object Get(string cacheKey, Func<object> factory)
+        {
+            return factory();
+        }
+
+        /// <inheritdoc />
+        public virtual IEnumerable<object> SearchByKey(string keyStartsWith)
+        {
+            return Enumerable.Empty<object>();
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<object> SearchByRegex(string regex)
+        {
+            return Enumerable.Empty<object>();
+        }
+
+        /// <inheritdoc />
+        public object Get(string key, Func<object> factory, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
+        {
+            return factory();
+        }
+
+        /// <inheritdoc />
+        public void Insert(string key, Func<object> factory, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
+        { }
+
+        /// <inheritdoc />
+        public virtual void Clear()
+        { }
+
+        /// <inheritdoc />
+        public virtual void Clear(string key)
+        { }
+
+        /// <inheritdoc />
+        public virtual void ClearOfType(string typeName)
+        { }
+
+        /// <inheritdoc />
+        public virtual void ClearOfType<T>()
+        { }
+
+        /// <inheritdoc />
+        public virtual void ClearOfType<T>(Func<string, T, bool> predicate)
+        { }
+
+        /// <inheritdoc />
+        public virtual void ClearByKey(string keyStartsWith)
+        { }
+
+        /// <inheritdoc />
+        public virtual void ClearByRegex(string regex)
+        { }
+    }
+}
@@ -13,7 +13,7 @@ namespace Umbraco.Core.Cache

        public static NoCacheRepositoryCachePolicy<TEntity, TId> Instance { get; } = new NoCacheRepositoryCachePolicy<TEntity, TId>();

-        public IRepositoryCachePolicy<TEntity, TId> Scoped(IRuntimeCacheProvider runtimeCache, IScope scope)
+        public IRepositoryCachePolicy<TEntity, TId> Scoped(IAppPolicyCache runtimeCache, IScope scope)
        {
            throw new NotImplementedException();
        }
@@ -1,66 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Web.Caching;
-
-namespace Umbraco.Core.Cache
-{
-    /// <summary>
-    /// Represents a cache provider that does not cache anything.
-    /// </summary>
-    public class NullCacheProvider : IRuntimeCacheProvider
-    {
-        private NullCacheProvider() { }
-
-        public static NullCacheProvider Instance { get; } = new NullCacheProvider();
-
-        public virtual void ClearAllCache()
-        { }
-
-        public virtual void ClearCacheItem(string key)
-        { }
-
-        public virtual void ClearCacheObjectTypes(string typeName)
-        { }
-
-        public virtual void ClearCacheObjectTypes<T>()
-        { }
-
-        public virtual void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate)
-        { }
-
-        public virtual void ClearCacheByKeySearch(string keyStartsWith)
-        { }
-
-        public virtual void ClearCacheByKeyExpression(string regexString)
-        { }
-
-        public virtual IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith)
-        {
-            return Enumerable.Empty<object>();
-        }
-
-        public IEnumerable<object> GetCacheItemsByKeyExpression(string regexString)
-        {
-            return Enumerable.Empty<object>();
-        }
-
-        public virtual object GetCacheItem(string cacheKey)
-        {
-            return default(object);
-        }
-
-        public virtual object GetCacheItem(string cacheKey, Func<object> getCacheItem)
-        {
-            return getCacheItem();
-        }
-
-        public object GetCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        {
-            return getCacheItem();
-        }
-
-        public void InsertCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        { }
-    }
-}
@@ -11,31 +11,142 @@ using CacheItemPriority = System.Web.Caching.CacheItemPriority;
 namespace Umbraco.Core.Cache
 {
    /// <summary>
-    /// Represents a cache provider that caches item in a <see cref="MemoryCache"/>.
-    /// A cache provider that wraps the logic of a System.Runtime.Caching.ObjectCache
+    /// Implements <see cref="IAppPolicyCache"/> on top of a <see cref="ObjectCache"/>.
    /// </summary>
-    /// <remarks>The <see cref="MemoryCache"/> is created with name "in-memory". That name is
-    /// used to retrieve configuration options. It does not identify the memory cache, i.e.
-    /// each instance of this class has its own, independent, memory cache.</remarks>
-    public class ObjectCacheRuntimeCacheProvider : IRuntimeCacheProvider
+    public class ObjectCacheAppCache : IAppPolicyCache
    {
        private readonly ReaderWriterLockSlim _locker = new ReaderWriterLockSlim(LockRecursionPolicy.SupportsRecursion);
-        internal ObjectCache MemoryCache;

        /// <summary>
-        /// Used for debugging
+        /// Initializes a new instance of the <see cref="ObjectCacheAppCache"/>.
        /// </summary>
-        internal Guid InstanceId { get; private set; }
-
-        public ObjectCacheRuntimeCacheProvider()
+        public ObjectCacheAppCache()
        {
+            // the MemoryCache is created with name "in-memory". That name is
+            // used to retrieve configuration options. It does not identify the memory cache, i.e.
+            // each instance of this class has its own, independent, memory cache.
            MemoryCache = new MemoryCache("in-memory");
-            InstanceId = Guid.NewGuid();
        }

-        #region Clear
+        /// <summary>
+        /// Gets the internal memory cache, for tests only!
+        /// </summary>
+        internal ObjectCache MemoryCache { get; private set; }

-        public virtual void ClearAllCache()
+        /// <inheritdoc />
+        public object Get(string key)
+        {
+            Lazy<object> result;
+            try
+            {
+                _locker.EnterReadLock();
+                result = MemoryCache.Get(key) as Lazy<object>; // null if key not found
+            }
+            finally
+            {
+                if (_locker.IsReadLockHeld)
+                    _locker.ExitReadLock();
+            }
+            return result == null ? null : FastDictionaryAppCacheBase.GetSafeLazyValue(result); // return exceptions as null
+        }
+
+        /// <inheritdoc />
+        public object Get(string key, Func<object> factory)
+        {
+            return Get(key, factory, null);
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<object> SearchByKey(string keyStartsWith)
+        {
+            KeyValuePair<string, object>[] entries;
+            try
+            {
+                _locker.EnterReadLock();
+                entries = MemoryCache
+                    .Where(x => x.Key.InvariantStartsWith(keyStartsWith))
+                    .ToArray(); // evaluate while locked
+            }
+            finally
+            {
+                if (_locker.IsReadLockHeld)
+                    _locker.ExitReadLock();
+            }
+            return entries
+                .Select(x => FastDictionaryAppCacheBase.GetSafeLazyValue((Lazy<object>)x.Value)) // return exceptions as null
+                .Where(x => x != null) // backward compat, don't store null values in the cache
+                .ToList();
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<object> SearchByRegex(string regex)
+        {
+            var compiled = new Regex(regex, RegexOptions.Compiled);
+
+            KeyValuePair<string, object>[] entries;
+            try
+            {
+                _locker.EnterReadLock();
+                entries = MemoryCache
+                    .Where(x => compiled.IsMatch(x.Key))
+                    .ToArray(); // evaluate while locked
+            }
+            finally
+            {
+                if (_locker.IsReadLockHeld)
+                    _locker.ExitReadLock();
+            }
+            return entries
+                .Select(x => FastDictionaryAppCacheBase.GetSafeLazyValue((Lazy<object>)x.Value)) // return exceptions as null
+                .Where(x => x != null) // backward compat, don't store null values in the cache
+                .ToList();
+        }
+
+        /// <inheritdoc />
+        public object Get(string key, Func<object> factory, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
+        {
+            // see notes in HttpRuntimeAppCache
+
+            Lazy<object> result;
+
+            using (var lck = new UpgradeableReadLock(_locker))
+            {
+                result = MemoryCache.Get(key) as Lazy<object>;
+                if (result == null || FastDictionaryAppCacheBase.GetSafeLazyValue(result, true) == null) // get non-created as NonCreatedValue & exceptions as null
+                {
+                    result = FastDictionaryAppCacheBase.GetSafeLazy(factory);
+                    var policy = GetPolicy(timeout, isSliding, removedCallback, dependentFiles);
+
+                    lck.UpgradeToWriteLock();
+                    //NOTE: This does an add or update
+                    MemoryCache.Set(key, result, policy);
+                }
+            }
+
+            //return result.Value;
+
+            var value = result.Value; // will not throw (safe lazy)
+            if (value is FastDictionaryAppCacheBase.ExceptionHolder eh) eh.Exception.Throw(); // throw once!
+            return value;
+        }
+
+        /// <inheritdoc />
+        public void Insert(string key, Func<object> factory, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
+        {
+            // NOTE - here also we must insert a Lazy<object> but we can evaluate it right now
+            // and make sure we don't store a null value.
+
+            var result = FastDictionaryAppCacheBase.GetSafeLazy(factory);
+            var value = result.Value; // force evaluation now
+            if (value == null) return; // do not store null values (backward compat)
+
+            var policy = GetPolicy(timeout, isSliding, removedCallback, dependentFiles);
+            //NOTE: This does an add or update
+            MemoryCache.Set(key, result, policy);
+        }
+
+        /// <inheritdoc />
+        public virtual void Clear()
        {
            try
            {
@@ -50,7 +161,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheItem(string key)
+        /// <inheritdoc />
+        public virtual void Clear(string key)
        {
            try
            {
@@ -65,7 +177,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheObjectTypes(string typeName)
+        /// <inheritdoc />
+        public virtual void ClearOfType(string typeName)
        {
            var type = TypeFinder.GetTypeByName(typeName);
            if (type == null) return;
@@ -79,7 +192,7 @@ namespace Umbraco.Core.Cache
                        // x.Value is Lazy<object> and not null, its value may be null
                        // remove null values as well, does not hurt
                        // get non-created as NonCreatedValue & exceptions as null
-                        var value = DictionaryCacheProviderBase.GetSafeLazyValue((Lazy<object>)x.Value, true);
+                        var value = FastDictionaryAppCacheBase.GetSafeLazyValue((Lazy<object>)x.Value, true);

                        // if T is an interface remove anything that implements that interface
                        // otherwise remove exact types (not inherited types)
@@ -96,12 +209,13 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheObjectTypes<T>()
+        /// <inheritdoc />
+        public virtual void ClearOfType<T>()
        {
            try
            {
                _locker.EnterWriteLock();
-                var typeOfT = typeof (T);
+                var typeOfT = typeof(T);
                var isInterface = typeOfT.IsInterface;
                foreach (var key in MemoryCache
                    .Where(x =>
@@ -109,7 +223,7 @@ namespace Umbraco.Core.Cache
                        // x.Value is Lazy<object> and not null, its value may be null
                        // remove null values as well, does not hurt
                        // get non-created as NonCreatedValue & exceptions as null
-                        var value = DictionaryCacheProviderBase.GetSafeLazyValue((Lazy<object>)x.Value, true);
+                        var value = FastDictionaryAppCacheBase.GetSafeLazyValue((Lazy<object>)x.Value, true);

                        // if T is an interface remove anything that implements that interface
                        // otherwise remove exact types (not inherited types)
@@ -127,7 +241,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate)
+        /// <inheritdoc />
+        public virtual void ClearOfType<T>(Func<string, T, bool> predicate)
        {
            try
            {
@@ -140,7 +255,7 @@ namespace Umbraco.Core.Cache
                        // x.Value is Lazy<object> and not null, its value may be null
                        // remove null values as well, does not hurt
                        // get non-created as NonCreatedValue & exceptions as null
-                        var value = DictionaryCacheProviderBase.GetSafeLazyValue((Lazy<object>)x.Value, true);
+                        var value = FastDictionaryAppCacheBase.GetSafeLazyValue((Lazy<object>)x.Value, true);
                        if (value == null) return true;

                        // if T is an interface remove anything that implements that interface
@@ -159,7 +274,8 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheByKeySearch(string keyStartsWith)
+        /// <inheritdoc />
+        public virtual void ClearByKey(string keyStartsWith)
        {
            try
            {
@@ -177,13 +293,16 @@ namespace Umbraco.Core.Cache
            }
        }

-        public virtual void ClearCacheByKeyExpression(string regexString)
+        /// <inheritdoc />
+        public virtual void ClearByRegex(string regex)
        {
+            var compiled = new Regex(regex, RegexOptions.Compiled);
+
            try
            {
                _locker.EnterWriteLock();
                foreach (var key in MemoryCache
-                    .Where(x => Regex.IsMatch(x.Key, regexString))
+                    .Where(x => compiled.IsMatch(x.Key))
                    .Select(x => x.Key)
                    .ToArray()) // ToArray required to remove
                    MemoryCache.Remove(key);
@@ -195,120 +314,6 @@ namespace Umbraco.Core.Cache
            }
        }

-        #endregion
-
-        #region Get
-
-        public IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith)
-        {
-            KeyValuePair<string, object>[] entries;
-            try
-            {
-                _locker.EnterReadLock();
-                entries = MemoryCache
-                    .Where(x => x.Key.InvariantStartsWith(keyStartsWith))
-                    .ToArray(); // evaluate while locked
-            }
-            finally
-            {
-                if (_locker.IsReadLockHeld)
-                    _locker.ExitReadLock();
-            }
-            return entries
-                .Select(x => DictionaryCacheProviderBase.GetSafeLazyValue((Lazy<object>)x.Value)) // return exceptions as null
-                .Where(x => x != null) // backward compat, don't store null values in the cache
-                .ToList();
-        }
-
-        public IEnumerable<object> GetCacheItemsByKeyExpression(string regexString)
-        {
-            KeyValuePair<string, object>[] entries;
-            try
-            {
-                _locker.EnterReadLock();
-                entries = MemoryCache
-                    .Where(x => Regex.IsMatch(x.Key, regexString))
-                    .ToArray(); // evaluate while locked
-            }
-            finally
-            {
-                if (_locker.IsReadLockHeld)
-                    _locker.ExitReadLock();
-            }
-            return entries
-                .Select(x => DictionaryCacheProviderBase.GetSafeLazyValue((Lazy<object>)x.Value)) // return exceptions as null
-                .Where(x => x != null) // backward compat, don't store null values in the cache
-                .ToList();
-        }
-
-        public object GetCacheItem(string cacheKey)
-        {
-            Lazy<object> result;
-            try
-            {
-                _locker.EnterReadLock();
-                result = MemoryCache.Get(cacheKey) as Lazy<object>; // null if key not found
-            }
-            finally
-            {
-                if (_locker.IsReadLockHeld)
-                    _locker.ExitReadLock();
-            }
-            return result == null ? null : DictionaryCacheProviderBase.GetSafeLazyValue(result); // return exceptions as null
-        }
-
-        public object GetCacheItem(string cacheKey, Func<object> getCacheItem)
-        {
-            return GetCacheItem(cacheKey, getCacheItem, null);
-        }
-
-        public object GetCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        {
-            // see notes in HttpRuntimeCacheProvider
-
-            Lazy<object> result;
-
-            using (var lck = new UpgradeableReadLock(_locker))
-            {
-                result = MemoryCache.Get(cacheKey) as Lazy<object>;
-                if (result == null || DictionaryCacheProviderBase.GetSafeLazyValue(result, true) == null) // get non-created as NonCreatedValue & exceptions as null
-                {
-                    result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
-                    var policy = GetPolicy(timeout, isSliding, removedCallback, dependentFiles);
-
-                    lck.UpgradeToWriteLock();
-                    //NOTE: This does an add or update
-                    MemoryCache.Set(cacheKey, result, policy);
-                }
-            }
-
-            //return result.Value;
-
-            var value = result.Value; // will not throw (safe lazy)
-            if (value is DictionaryCacheProviderBase.ExceptionHolder eh) eh.Exception.Throw(); // throw once!
-            return value;
-        }
-
-        #endregion
-
-        #region Insert
-
-        public void InsertCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        {
-            // NOTE - here also we must insert a Lazy<object> but we can evaluate it right now
-            // and make sure we don't store a null value.
-
-            var result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
-            var value = result.Value; // force evaluation now
-            if (value == null) return; // do not store null values (backward compat)
-
-            var policy = GetPolicy(timeout, isSliding, removedCallback, dependentFiles);
-            //NOTE: This does an add or update
-            MemoryCache.Set(cacheKey, result, policy);
-        }
-
-        #endregion
-
        private static CacheItemPolicy GetPolicy(TimeSpan? timeout = null, bool isSliding = false, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
        {
            var absolute = isSliding ? ObjectCache.InfiniteAbsoluteExpiration : (timeout == null ? ObjectCache.InfiniteAbsoluteExpiration : DateTime.Now.Add(timeout.Value));
@@ -15,8 +15,8 @@ namespace Umbraco.Core.Cache
        /// <summary>
        /// Initializes a new instance of the <see cref="PayloadCacheRefresherBase{TInstanceType, TPayload}"/>.
        /// </summary>
-        /// <param name="cacheHelper">A cache helper.</param>
-        protected PayloadCacheRefresherBase(CacheHelper cacheHelper) : base(cacheHelper)
+        /// <param name="appCaches">A cache helper.</param>
+        protected PayloadCacheRefresherBase(AppCaches appCaches) : base(appCaches)
        { }

        #region Json
@@ -13,16 +13,16 @@ namespace Umbraco.Core.Cache
    internal abstract class RepositoryCachePolicyBase<TEntity, TId> : IRepositoryCachePolicy<TEntity, TId>
        where TEntity : class, IEntity
    {
-        private readonly IRuntimeCacheProvider _globalCache;
+        private readonly IAppPolicyCache _globalCache;
        private readonly IScopeAccessor _scopeAccessor;

-        protected RepositoryCachePolicyBase(IRuntimeCacheProvider globalCache, IScopeAccessor scopeAccessor)
+        protected RepositoryCachePolicyBase(IAppPolicyCache globalCache, IScopeAccessor scopeAccessor)
        {
            _globalCache = globalCache ?? throw new ArgumentNullException(nameof(globalCache));
            _scopeAccessor = scopeAccessor ?? throw new ArgumentNullException(nameof(scopeAccessor));
        }

-        protected IRuntimeCacheProvider Cache
+        protected IAppPolicyCache Cache
        {
            get
            {
@@ -32,9 +32,9 @@ namespace Umbraco.Core.Cache
                    case RepositoryCacheMode.Default:
                        return _globalCache;
                    case RepositoryCacheMode.Scoped:
-                        return ambientScope.IsolatedRuntimeCache.GetOrCreateCache<TEntity>();
+                        return ambientScope.IsolatedCaches.GetOrCreate<TEntity>();
                    case RepositoryCacheMode.None:
-                        return NullCacheProvider.Instance;
+                        return NoAppCache.Instance;
                    default:
                        throw new NotSupportedException($"Repository cache mode {ambientScope.RepositoryCacheMode} is not supported.");
                }
@@ -16,7 +16,7 @@ namespace Umbraco.Core.Cache
    internal class SingleItemsOnlyRepositoryCachePolicy<TEntity, TId> : DefaultRepositoryCachePolicy<TEntity, TId>
        where TEntity : class, IEntity
    {
-        public SingleItemsOnlyRepositoryCachePolicy(IRuntimeCacheProvider cache, IScopeAccessor scopeAccessor, RepositoryCachePolicyOptions options)
+        public SingleItemsOnlyRepositoryCachePolicy(IAppPolicyCache cache, IScopeAccessor scopeAccessor, RepositoryCachePolicyOptions options)
            : base(cache, scopeAccessor, options)
        { }

@@ -1,79 +0,0 @@
-using System;
-using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text.RegularExpressions;
-
-namespace Umbraco.Core.Cache
-{
-    /// <summary>
-    /// Represents a cache provider that statically caches item in a concurrent dictionary.
-    /// </summary>
-    public class StaticCacheProvider : ICacheProvider
-    {
-        internal readonly ConcurrentDictionary<string, object> StaticCache = new ConcurrentDictionary<string, object>();
-
-        public virtual void ClearAllCache()
-        {
-            StaticCache.Clear();
-        }
-
-        public virtual void ClearCacheItem(string key)
-        {
-            object val;
-            StaticCache.TryRemove(key, out val);
-        }
-
-        public virtual void ClearCacheObjectTypes(string typeName)
-        {
-            StaticCache.RemoveAll(kvp => kvp.Value != null && kvp.Value.GetType().ToString().InvariantEquals(typeName));
-        }
-
-        public virtual void ClearCacheObjectTypes<T>()
-        {
-            var typeOfT = typeof(T);
-            StaticCache.RemoveAll(kvp => kvp.Value != null && kvp.Value.GetType() == typeOfT);
-        }
-
-        public virtual void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate)
-        {
-            var typeOfT = typeof(T);
-            StaticCache.RemoveAll(kvp => kvp.Value != null && kvp.Value.GetType() == typeOfT && predicate(kvp.Key, (T)kvp.Value));
-        }
-
-        public virtual void ClearCacheByKeySearch(string keyStartsWith)
-        {
-            StaticCache.RemoveAll(kvp => kvp.Key.InvariantStartsWith(keyStartsWith));
-        }
-
-        public virtual void ClearCacheByKeyExpression(string regexString)
-        {
-            StaticCache.RemoveAll(kvp => Regex.IsMatch(kvp.Key, regexString));
-        }
-
-        public virtual IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith)
-        {
-            return (from KeyValuePair<string, object> c in StaticCache
-                    where c.Key.InvariantStartsWith(keyStartsWith)
-                    select c.Value).ToList();
-        }
-
-        public IEnumerable<object> GetCacheItemsByKeyExpression(string regexString)
-        {
-            return (from KeyValuePair<string, object> c in StaticCache
-                    where Regex.IsMatch(c.Key, regexString)
-                    select c.Value).ToList();
-        }
-
-        public virtual object GetCacheItem(string cacheKey)
-        {
-            var result = StaticCache[cacheKey];
-            return result;
-        }
-
-        public virtual object GetCacheItem(string cacheKey, Func<object> getCacheItem)
-        {
-            return StaticCache.GetOrAdd(cacheKey, key => getCacheItem());
-        }
-    }
-}
@@ -14,9 +14,9 @@ namespace Umbraco.Core.Cache
        /// <summary>
        /// Initializes a new instance of the <see cref="TypedCacheRefresherBase{TInstanceType, TEntityType}"/>.
        /// </summary>
-        /// <param name="cacheHelper">A cache helper.</param>
-        protected TypedCacheRefresherBase(CacheHelper cacheHelper)
-            : base(cacheHelper)
+        /// <param name="appCaches">A cache helper.</param>
+        protected TypedCacheRefresherBase(AppCaches appCaches)
+            : base(appCaches)
        { }

        #region Refresher
@@ -4,14 +4,14 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Web.Caching;
-using CacheItemPriority = System.Web.Caching.CacheItemPriority;

 namespace Umbraco.Core.Cache
 {
    /// <summary>
-    /// A CacheProvider that wraps the logic of the HttpRuntime.Cache
+    /// Implements <see cref="IAppPolicyCache"/> on top of a <see cref="System.Web.Caching.Cache"/>.
    /// </summary>
-    internal class HttpRuntimeCacheProvider : DictionaryCacheProviderBase, IRuntimeCacheProvider
+    /// <remarks>The underlying cache is expected to be HttpRuntime.Cache.</remarks>
+    internal class WebCachingAppCache : FastDictionaryAppCacheBase, IAppPolicyCache
    {
        // locker object that supports upgradeable read locking
        // does not need to support recursion if we implement the cache correctly and ensure
@@ -21,16 +21,43 @@ namespace Umbraco.Core.Cache
        private readonly System.Web.Caching.Cache _cache;

        /// <summary>
-        /// Used for debugging
+        /// Initializes a new instance of the <see cref="WebCachingAppCache"/> class.
        /// </summary>
-        internal Guid InstanceId { get; private set; }
-
-        public HttpRuntimeCacheProvider(System.Web.Caching.Cache cache)
+        public WebCachingAppCache(System.Web.Caching.Cache cache)
        {
            _cache = cache;
-            InstanceId = Guid.NewGuid();
        }

+        /// <inheritdoc />
+        public override object Get(string key, Func<object> factory)
+        {
+            return Get(key, factory, null, dependentFiles: null);
+        }
+
+        /// <inheritdoc />
+        public object Get(string key, Func<object> factory, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
+        {
+            CacheDependency dependency = null;
+            if (dependentFiles != null && dependentFiles.Any())
+            {
+                dependency = new CacheDependency(dependentFiles);
+            }
+            return Get(key, factory, timeout, isSliding, priority, removedCallback, dependency);
+        }
+
+        /// <inheritdoc />
+        public void Insert(string key, Func<object> factory, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
+        {
+            CacheDependency dependency = null;
+            if (dependentFiles != null && dependentFiles.Any())
+            {
+                dependency = new CacheDependency(dependentFiles);
+            }
+            Insert(key, factory, timeout, isSliding, priority, removedCallback, dependency);
+        }
+
+        #region Dictionary
+
        protected override IEnumerable<DictionaryEntry> GetDictionaryEntries()
        {
            const string prefix = CacheItemPrefix + "-";
@@ -48,6 +75,8 @@ namespace Umbraco.Core.Cache
            return _cache.Get(key);
        }

+        #endregion
+
        #region Lock

        protected override void EnterReadLock()
@@ -74,33 +103,9 @@ namespace Umbraco.Core.Cache

        #endregion

-        #region Get
-
-        /// <summary>
-        /// Gets (and adds if necessary) an item from the cache with all of the default parameters
-        /// </summary>
-        /// <param name="cacheKey"></param>
-        /// <param name="getCacheItem"></param>
-        /// <returns></returns>
-        public override object GetCacheItem(string cacheKey, Func<object> getCacheItem)
+        private object Get(string key, Func<object> factory, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, CacheDependency dependency = null)
        {
-            return GetCacheItem(cacheKey, getCacheItem, null, dependentFiles: null);
-        }
-
-        /// <summary>
-        /// This overload is here for legacy purposes
-        /// </summary>
-        /// <param name="cacheKey"></param>
-        /// <param name="getCacheItem"></param>
-        /// <param name="timeout"></param>
-        /// <param name="isSliding"></param>
-        /// <param name="priority"></param>
-        /// <param name="removedCallback"></param>
-        /// <param name="dependency"></param>
-        /// <returns></returns>
-        internal object GetCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, CacheDependency dependency = null)
-        {
-            cacheKey = GetCacheKey(cacheKey);
+            key = GetCacheKey(key);

            // NOTE - because we don't know what getCacheItem does, how long it will take and whether it will hang,
            // getCacheItem should run OUTSIDE of the global application lock else we run into lock contention and
@@ -133,7 +138,7 @@ namespace Umbraco.Core.Cache
            try
            {
                _locker.EnterReadLock();
-                result = _cache.Get(cacheKey) as Lazy<object>; // null if key not found
+                result = _cache.Get(key) as Lazy<object>; // null if key not found
            }
            finally
            {
@@ -145,7 +150,7 @@ namespace Umbraco.Core.Cache

            using (var lck = new UpgradeableReadLock(_locker))
            {
-                result = _cache.Get(cacheKey) as Lazy<object>; // null if key not found
+                result = _cache.Get(key) as Lazy<object>; // null if key not found

                // cannot create value within the lock, so if result.IsValueCreated is false, just
                // do nothing here - means that if creation throws, a race condition could cause
@@ -153,13 +158,13 @@ namespace Umbraco.Core.Cache

                if (result == null || GetSafeLazyValue(result, true) == null) // get non-created as NonCreatedValue & exceptions as null
                {
-                    result = GetSafeLazy(getCacheItem);
+                    result = GetSafeLazy(factory);
                    var absolute = isSliding ? System.Web.Caching.Cache.NoAbsoluteExpiration : (timeout == null ? System.Web.Caching.Cache.NoAbsoluteExpiration : DateTime.Now.Add(timeout.Value));
                    var sliding = isSliding == false ? System.Web.Caching.Cache.NoSlidingExpiration : (timeout ?? System.Web.Caching.Cache.NoSlidingExpiration);

                    lck.UpgradeToWriteLock();
                    //NOTE: 'Insert' on System.Web.Caching.Cache actually does an add or update!
-                    _cache.Insert(cacheKey, result, dependency, absolute, sliding, priority, removedCallback);
+                    _cache.Insert(key, result, dependency, absolute, sliding, priority, removedCallback);
                }
            }

@@ -175,31 +180,7 @@ namespace Umbraco.Core.Cache
            return value;
        }

-        public object GetCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        {
-            CacheDependency dependency = null;
-            if (dependentFiles != null && dependentFiles.Any())
-            {
-                dependency = new CacheDependency(dependentFiles);
-            }
-            return GetCacheItem(cacheKey, getCacheItem, timeout, isSliding, priority, removedCallback, dependency);
-        }
-
-        #endregion
-
-        #region Insert
-
-        /// <summary>
-        /// This overload is here for legacy purposes
-        /// </summary>
-        /// <param name="cacheKey"></param>
-        /// <param name="getCacheItem"></param>
-        /// <param name="timeout"></param>
-        /// <param name="isSliding"></param>
-        /// <param name="priority"></param>
-        /// <param name="removedCallback"></param>
-        /// <param name="dependency"></param>
-        internal void InsertCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, CacheDependency dependency = null)
+        private void Insert(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, CacheDependency dependency = null)
        {
            // NOTE - here also we must insert a Lazy<object> but we can evaluate it right now
            // and make sure we don't store a null value.
@@ -225,17 +206,5 @@ namespace Umbraco.Core.Cache
                    _locker.ExitWriteLock();
            }
        }
-
-        public void InsertCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        {
-            CacheDependency dependency = null;
-            if (dependentFiles != null && dependentFiles.Any())
-            {
-                dependency = new CacheDependency(dependentFiles);
-            }
-            InsertCacheItem(cacheKey, getCacheItem, timeout, isSliding, priority, removedCallback, dependency);
-        }
-
-        #endregion
    }
 }
@@ -1,35 +0,0 @@
-using System;
-using Umbraco.Core.Exceptions;
-
-namespace Umbraco.Core.CodeAnnotations
-{
-    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
-    internal class ActionMetadataAttribute : Attribute
-    {
-        public string Category { get; }
-        public string Name { get; }
-
-        /// <summary>
-        /// Constructor used to assign a Category, since no name is assigned it will try to be translated from the language files based on the action's alias
-        /// </summary>
-        /// <param name="category"></param>
-        public ActionMetadataAttribute(string category)
-        {
-            if (string.IsNullOrWhiteSpace(category)) throw new ArgumentNullOrEmptyException(nameof(category));
-            Category = category;
-        }
-
-        /// <summary>
-        /// Constructor used to assign an explicit name and category
-        /// </summary>
-        /// <param name="category"></param>
-        /// <param name="name"></param>
-        public ActionMetadataAttribute(string category, string name)
-        {
-            if (string.IsNullOrWhiteSpace(category)) throw new ArgumentNullOrEmptyException(nameof(category));
-            if (string.IsNullOrWhiteSpace(name)) throw new ArgumentNullOrEmptyException(nameof(name));
-            Category = category;
-            Name = name;
-        }
-    }
-}
@@ -70,10 +70,7 @@ namespace Umbraco.Core.Collections
        /// The number of elements contained in the <see cref="T:System.Collections.ICollection"/>.
        /// </returns>
        /// <filterpriority>2</filterpriority>
-        public int Count
-        {
-            get { return GetThreadSafeClone().Count; }
-        }
+        public int Count => GetThreadSafeClone().Count;

        /// <summary>
        /// Gets a value indicating whether the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
@@ -81,10 +78,7 @@ namespace Umbraco.Core.Collections
        /// <returns>
        /// true if the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only; otherwise, false.
        /// </returns>
-        public bool IsReadOnly
-        {
-            get { return false; }
-        }
+        public bool IsReadOnly => false;

        /// <summary>
        /// Adds an item to the <see cref="T:System.Collections.Generic.ICollection`1"/>.
@@ -125,6 +125,18 @@ namespace Umbraco.Core.Collections

        }

+        public void ReplaceAll(IEnumerable<TValue> values)
+        {
+            if (values == null) throw new ArgumentNullException(nameof(values));
+
+            Clear();
+
+            foreach (var value in values)
+            {
+                Add(value);
+            }
+        }
+
        public bool Remove(TKey key)
        {
            if (!Indecies.ContainsKey(key)) return false;
@@ -12,11 +12,36 @@ using Umbraco.Core.Services.Implement;

 namespace Umbraco.Core.Components
 {
-    public sealed class AuditEventsComponent : UmbracoComponentBase, IUmbracoCoreComponent
+    public sealed class AuditEventsComponent : IComponent
    {
-        private IAuditService _auditService;
-        private IUserService _userService;
-        private IEntityService _entityService;
+        private readonly IAuditService _auditService;
+        private readonly IUserService _userService;
+        private readonly IEntityService _entityService;
+
+        public AuditEventsComponent(IAuditService auditService, IUserService userService, IEntityService entityService)
+        {
+            _auditService = auditService;
+            _userService = userService;
+            _entityService = entityService;
+        }
+
+        public void Initialize()
+        {
+            UserService.SavedUserGroup += OnSavedUserGroupWithUsers;
+
+            UserService.SavedUser += OnSavedUser;
+            UserService.DeletedUser += OnDeletedUser;
+            UserService.UserGroupPermissionsAssigned += UserGroupPermissionAssigned;
+
+            MemberService.Saved += OnSavedMember;
+            MemberService.Deleted += OnDeletedMember;
+            MemberService.AssignedRoles += OnAssignedRoles;
+            MemberService.RemovedRoles += OnRemovedRoles;
+            MemberService.Exported += OnMemberExported;
+        }
+
+        public void Terminate()
+        { }

        private IUser CurrentPerformingUser
        {
@@ -46,25 +71,6 @@ namespace Umbraco.Core.Components
            }
        }

-        public void Initialize(IAuditService auditService, IUserService userService, IEntityService entityService)
-        {
-            _auditService = auditService;
-            _userService = userService;
-            _entityService = entityService;
-
-            UserService.SavedUserGroup += OnSavedUserGroupWithUsers;
-
-            UserService.SavedUser += OnSavedUser;
-            UserService.DeletedUser += OnDeletedUser;
-            UserService.UserGroupPermissionsAssigned += UserGroupPermissionAssigned;
-
-            MemberService.Saved += OnSavedMember;
-            MemberService.Deleted += OnDeletedMember;
-            MemberService.AssignedRoles += OnAssignedRoles;
-            MemberService.RemovedRoles += OnRemovedRoles;
-            MemberService.Exported += OnMemberExported;
-        }
-
        private string FormatEmail(IMember member)
        {
            return member == null ? string.Empty : member.Email.IsNullOrWhiteSpace() ? "" : $"<{member.Email}>";
@@ -0,0 +1,5 @@
+namespace Umbraco.Core.Components
+{
+    public sealed class AuditEventsComposer : ComponentComposer<AuditEventsComponent>, ICoreComposer
+    { }
+}
@@ -1,368 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Reflection;
-using System.Text;
-using LightInject;
-using Umbraco.Core.Collections;
-using Umbraco.Core.Exceptions;
-using Umbraco.Core.Logging;
-using Umbraco.Core.Scoping;
-
-namespace Umbraco.Core.Components
-{
-    // note: this class is NOT thread-safe in any ways
-
-    internal class BootLoader
-    {
-        private readonly IServiceContainer _container;
-        private readonly ProfilingLogger _proflog;
-        private readonly ILogger _logger;
-        private IUmbracoComponent[] _components;
-        private bool _booted;
-
-        private const int LogThresholdMilliseconds = 100;
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="BootLoader"/> class.
-        /// </summary>
-        /// <param name="container">The application container.</param>
-        public BootLoader(IServiceContainer container)
-        {
-            _container = container ?? throw new ArgumentNullException(nameof(container));
-            _proflog = container.GetInstance<ProfilingLogger>();
-            _logger = container.GetInstance<ILogger>();
-        }
-
-        private class EnableInfo
-        {
-            public bool Enabled;
-            public int Weight = -1;
-        }
-
-        public void Boot(IEnumerable<Type> componentTypes, RuntimeLevel level)
-        {
-            if (_booted) throw new InvalidOperationException("Can not boot, has already booted.");
-
-            var orderedComponentTypes = PrepareComponentTypes(componentTypes, level);
-
-            InstanciateComponents(orderedComponentTypes);
-            ComposeComponents(level);
-
-            using (var scope = _container.GetInstance<IScopeProvider>().CreateScope())
-            {
-                InitializeComponents();
-                scope.Complete();
-            }
-
-            // rejoice!
-            _booted = true;
-        }
-
-        private IEnumerable<Type> PrepareComponentTypes(IEnumerable<Type> componentTypes, RuntimeLevel level)
-        {
-            using (_proflog.DebugDuration<BootLoader>("Preparing component types.", "Prepared component types."))
-            {
-                return PrepareComponentTypes2(componentTypes, level);
-            }
-        }
-
-        private IEnumerable<Type> PrepareComponentTypes2(IEnumerable<Type> componentTypes, RuntimeLevel level)
-        {
-            // create a list, remove those that cannot be enabled due to runtime level
-            var componentTypeList = componentTypes
-                .Where(x =>
-                {
-                    // use the min level specified by the attribute if any
-                    // otherwise, user components have Run min level, anything else is Unknown (always run)
-                    var attr = x.GetCustomAttribute<RuntimeLevelAttribute>();
-                    var minLevel = attr?.MinLevel ?? (x.Implements<IUmbracoUserComponent>() ? RuntimeLevel.Run : RuntimeLevel.Unknown);
-                    return level >= minLevel;
-                })
-                .ToList();
-
-            // cannot remove that one - ever
-            if (componentTypeList.Contains(typeof(UmbracoCoreComponent)) == false)
-                componentTypeList.Add(typeof(UmbracoCoreComponent));
-
-            // enable or disable components
-            EnableDisableComponents(componentTypeList);
-
-            // sort the components according to their dependencies
-            var requirements = new Dictionary<Type, List<Type>>();
-            foreach (var type in componentTypeList) requirements[type] = null;
-            foreach (var type in componentTypeList)
-            {
-                GatherRequirementsFromRequireAttribute(type, componentTypeList, requirements);
-                GatherRequirementsFromRequiredAttribute(type, componentTypeList, requirements);
-            }
-
-            // only for debugging, this is verbose
-            //_logger.Debug<BootLoader>(GetComponentsReport(requirements));
-
-            // sort components
-            var graph = new TopoGraph<Type, KeyValuePair<Type, List<Type>>>(kvp => kvp.Key, kvp => kvp.Value);
-            graph.AddItems(requirements);
-            List<Type> sortedComponentTypes;
-            try
-            {
-                sortedComponentTypes = graph.GetSortedItems().Select(x => x.Key).ToList();
-            }
-            catch (Exception e)
-            {
-                // in case of an error, force-dump everything to log
-                _logger.Info<BootLoader>("Component Report:\r\n{ComponentReport}", GetComponentsReport(requirements));
-                _logger.Error<BootLoader>(e, "Failed to sort compontents.");
-                throw;
-            }
-
-            // bit verbose but should help for troubleshooting
-            var text = "Ordered Components: " + Environment.NewLine + string.Join(Environment.NewLine, sortedComponentTypes) + Environment.NewLine;
-            Console.WriteLine(text);
-            _logger.Debug<BootLoader>("Ordered Components: {SortedComponentTypes}", sortedComponentTypes);
-
-            return sortedComponentTypes;
-        }
-
-        private static string GetComponentsReport(Dictionary<Type, List<Type>> requirements)
-        {
-            var text = new StringBuilder();
-            text.AppendLine("Components & Dependencies:");
-            text.AppendLine();
-
-            foreach (var kvp in requirements)
-            {
-                var type = kvp.Key;
-
-                text.AppendLine(type.FullName);
-                foreach (var attribute in type.GetCustomAttributes<RequireComponentAttribute>())
-                    text.AppendLine("  -> " + attribute.RequiredType + (attribute.Weak.HasValue
-                        ? (attribute.Weak.Value ? " (weak)" : (" (strong" + (requirements.ContainsKey(attribute.RequiredType) ? ", missing" : "") + ")"))
-                        : ""));
-                foreach (var attribute in type.GetCustomAttributes<RequiredComponentAttribute>())
-                    text.AppendLine("  -< " + attribute.RequiringType);
-                foreach (var i in type.GetInterfaces())
-                {
-                    text.AppendLine("  : " + i.FullName);
-                    foreach (var attribute in i.GetCustomAttributes<RequireComponentAttribute>())
-                        text.AppendLine("    -> " + attribute.RequiredType + (attribute.Weak.HasValue
-                            ? (attribute.Weak.Value ? " (weak)" : (" (strong" + (requirements.ContainsKey(attribute.RequiredType) ? ", missing" : "") + ")"))
-                            : ""));
-                    foreach (var attribute in i.GetCustomAttributes<RequiredComponentAttribute>())
-                        text.AppendLine("    -< " + attribute.RequiringType);
-                }
-                if (kvp.Value != null)
-                    foreach (var t in kvp.Value)
-                        text.AppendLine("  = " + t);
-                text.AppendLine();
-            }
-            text.AppendLine("/");
-            text.AppendLine();
-            return text.ToString();
-        }
-
-        private static void EnableDisableComponents(ICollection<Type> types)
-        {
-            var enabled = new Dictionary<Type, EnableInfo>();
-
-            // process the enable/disable attributes
-            // these two attributes are *not* inherited and apply to *classes* only (not interfaces).
-            // remote declarations (when a component enables/disables *another* component)
-            // have priority over local declarations (when a component disables itself) so that
-            // ppl can enable components that, by default, are disabled.
-            // what happens in case of conflicting remote declarations is unspecified. more
-            // precisely, the last declaration to be processed wins, but the order of the
-            // declarations depends on the type finder and is unspecified.
-            foreach (var componentType in types)
-            {
-                foreach (var attr in componentType.GetCustomAttributes<EnableComponentAttribute>())
-                {
-                    var type = attr.EnabledType ?? componentType;
-                    if (enabled.TryGetValue(type, out var enableInfo) == false) enableInfo = enabled[type] = new EnableInfo();
-                    var weight = type == componentType ? 1 : 2;
-                    if (enableInfo.Weight > weight) continue;
-
-                    enableInfo.Enabled = true;
-                    enableInfo.Weight = weight;
-                }
-                foreach (var attr in componentType.GetCustomAttributes<DisableComponentAttribute>())
-                {
-                    var type = attr.DisabledType ?? componentType;
-                    if (type == typeof(UmbracoCoreComponent)) throw new InvalidOperationException("Cannot disable UmbracoCoreComponent.");
-                    if (enabled.TryGetValue(type, out var enableInfo) == false) enableInfo = enabled[type] = new EnableInfo();
-                    var weight = type == componentType ? 1 : 2;
-                    if (enableInfo.Weight > weight) continue;
-
-                    enableInfo.Enabled = false;
-                    enableInfo.Weight = weight;
-                }
-            }
-
-            // remove components that end up being disabled
-            foreach (var kvp in enabled.Where(x => x.Value.Enabled == false))
-                types.Remove(kvp.Key);
-        }
-
-        private static void GatherRequirementsFromRequireAttribute(Type type, ICollection<Type> types, IDictionary<Type, List<Type>> requirements)
-        {
-            // get 'require' attributes
-            // these attributes are *not* inherited because we want to "custom-inherit" for interfaces only
-            var requireAttributes = type
-                .GetInterfaces().SelectMany(x => x.GetCustomAttributes<RequireComponentAttribute>()) // those marking interfaces
-                .Concat(type.GetCustomAttributes<RequireComponentAttribute>()); // those marking the component
-
-            // what happens in case of conflicting attributes (different strong/weak for same type) is not specified.
-            foreach (var attr in requireAttributes)
-            {
-                if (attr.RequiredType == type) continue; // ignore self-requirements (+ exclude in implems, below)
-
-                // requiring an interface = require any enabled component implementing that interface
-                // unless strong, and then require at least one enabled component implementing that interface
-                if (attr.RequiredType.IsInterface)
-                {
-                    var implems = types.Where(x => x != type && attr.RequiredType.IsAssignableFrom(x)).ToList();
-                    if (implems.Count > 0)
-                    {
-                        if (requirements[type] == null) requirements[type] = new List<Type>();
-                        requirements[type].AddRange(implems);
-                    }
-                    else if (attr.Weak == false) // if explicitely set to !weak, is strong, else is weak
-                        throw new Exception($"Broken component dependency: {type.FullName} -> {attr.RequiredType.FullName}.");
-                }
-                // requiring a class = require that the component is enabled
-                // unless weak, and then requires it if it is enabled
-                else
-                {
-                    if (types.Contains(attr.RequiredType))
-                    {
-                        if (requirements[type] == null) requirements[type] = new List<Type>();
-                        requirements[type].Add(attr.RequiredType);
-                    }
-                    else if (attr.Weak != true) // if not explicitely set to weak, is strong
-                        throw new Exception($"Broken component dependency: {type.FullName} -> {attr.RequiredType.FullName}.");
-                }
-            }
-        }
-
-        private static void GatherRequirementsFromRequiredAttribute(Type type, ICollection<Type> types, IDictionary<Type, List<Type>> requirements)
-        {
-            // get 'required' attributes
-            // fixme explain
-            var requiredAttributes = type
-                .GetInterfaces().SelectMany(x => x.GetCustomAttributes<RequiredComponentAttribute>())
-                .Concat(type.GetCustomAttributes<RequiredComponentAttribute>());
-
-            foreach (var attr in requiredAttributes)
-            {
-                if (attr.RequiringType == type) continue; // ignore self-requirements (+ exclude in implems, below)
-
-                if (attr.RequiringType.IsInterface)
-                {
-                    var implems = types.Where(x => x != type && attr.RequiringType.IsAssignableFrom(x)).ToList();
-                    foreach (var implem in implems)
-                    {
-                        if (requirements[implem] == null) requirements[implem] = new List<Type>();
-                        requirements[implem].Add(type);
-                    }
-                }
-                else
-                {
-                    if (types.Contains(attr.RequiringType))
-                    {
-                        if (requirements[attr.RequiringType] == null) requirements[attr.RequiringType] = new List<Type>();
-                        requirements[attr.RequiringType].Add(type);
-                    }
-                }
-            }
-        }
-
-        private void InstanciateComponents(IEnumerable<Type> types)
-        {
-            using (_proflog.DebugDuration<BootLoader>("Instanciating components.", "Instanciated components."))
-            {
-                _components = types.Select(x => (IUmbracoComponent) Activator.CreateInstance(x)).ToArray();
-            }
-        }
-
-        private void ComposeComponents(RuntimeLevel level)
-        {
-            using (_proflog.DebugDuration<BootLoader>($"Composing components. (log when >{LogThresholdMilliseconds}ms)", "Composed components."))
-            {
-                var composition = new Composition(_container, level);
-                foreach (var component in _components)
-                {
-                    var componentType = component.GetType();
-                    using (_proflog.DebugDuration<BootLoader>($"Composing {componentType.FullName}.", $"Composed {componentType.FullName}.", thresholdMilliseconds: LogThresholdMilliseconds))
-                    {
-                        component.Compose(composition);
-                    }
-                }
-            }
-        }
-
-        private void InitializeComponents()
-        {
-            // use a container scope to ensure that PerScope instances are disposed
-            // components that require instances that should not survive should register them with PerScope lifetime
-            using (_proflog.DebugDuration<BootLoader>($"Initializing components. (log when >{LogThresholdMilliseconds}ms)", "Initialized components."))
-            using (_container.BeginScope())
-            {
-                foreach (var component in _components)
-                {
-                    var componentType = component.GetType();
-                    var initializers = componentType.GetMethods(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)
-                        .Where(x => x.Name == "Initialize" && x.IsGenericMethod == false);
-                    using (_proflog.DebugDuration<BootLoader>($"Initializing {componentType.FullName}.", $"Initialised {componentType.FullName}.", thresholdMilliseconds: LogThresholdMilliseconds))
-                    {
-                        foreach (var initializer in initializers)
-                        {
-                            var parameters = initializer.GetParameters()
-                                .Select(x => GetParameter(componentType, x.ParameterType))
-                                .ToArray();
-                            initializer.Invoke(component, parameters);
-                        }
-                    }
-                }
-            }
-        }
-
-        private object GetParameter(Type componentType, Type parameterType)
-        {
-            object param;
-
-            try
-            {
-                param = _container.TryGetInstance(parameterType);
-            }
-            catch (Exception e)
-            {
-                throw new BootFailedException($"Could not get parameter of type {parameterType.FullName} for component {componentType.FullName}.", e);
-            }
-
-            if (param == null) throw new BootFailedException($"Could not get parameter of type {parameterType.FullName} for component {componentType.FullName}.");
-            return param;
-        }
-
-        public void Terminate()
-        {
-            if (_booted == false)
-            {
-                _proflog.Logger.Warn<BootLoader>("Cannot terminate, has not booted.");
-                return;
-            }
-
-            using (_proflog.DebugDuration<BootLoader>($"Terminating. (log components when >{LogThresholdMilliseconds}ms)", "Terminated."))
-            {
-                for (var i = _components.Length - 1; i >= 0; i--) // terminate components in reverse order
-                {
-                    var component = _components[i];
-                    var componentType = component.GetType();
-                    using (_proflog.DebugDuration<BootLoader>($"Terminating {componentType.FullName}.", $"Terminated {componentType.FullName}.", thresholdMilliseconds: LogThresholdMilliseconds))
-                    {
-                        component.Terminate();
-                    }
-                }
-            }
-        }
-    }
-}
@@ -0,0 +1,54 @@
+using System.Collections.Generic;
+using System.Linq;
+using Umbraco.Core.Composing;
+using Umbraco.Core.Logging;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Represents the collection of <see cref="IComponent"/> implementations.
+    /// </summary>
+    public class ComponentCollection : BuilderCollectionBase<IComponent>
+    {
+        private const int LogThresholdMilliseconds = 100;
+
+        private readonly IProfilingLogger _logger;
+
+        public ComponentCollection(IEnumerable<IComponent> items, IProfilingLogger logger)
+            : base(items)
+        {
+            _logger = logger;
+        }
+
+        public void Initialize()
+        {
+            using (_logger.DebugDuration<ComponentCollection>($"Initializing. (log components when >{LogThresholdMilliseconds}ms)", "Initialized."))
+            {
+                foreach (var component in this.Reverse()) // terminate components in reverse order
+                {
+                    var componentType = component.GetType();
+                    using (_logger.DebugDuration<ComponentCollection>($"Initializing {componentType.FullName}.", $"Initialized {componentType.FullName}.", thresholdMilliseconds: LogThresholdMilliseconds))
+                    {
+                        component.Initialize();
+                    }
+                }
+            }
+        }
+
+        public void Terminate()
+        {
+            using (_logger.DebugDuration<ComponentCollection>($"Terminating. (log components when >{LogThresholdMilliseconds}ms)", "Terminated."))
+            {
+                foreach (var component in this.Reverse()) // terminate components in reverse order
+                {
+                    var componentType = component.GetType();
+                    using (_logger.DebugDuration<ComponentCollection>($"Terminating {componentType.FullName}.", $"Terminated {componentType.FullName}.", thresholdMilliseconds: LogThresholdMilliseconds))
+                    {
+                        component.Terminate();
+                        component.DisposeIfDisposable();
+                    }
+                }
+            }
+        }
+    }
+}
@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using Umbraco.Core.Composing;
+using Umbraco.Core.Logging;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Builds a <see cref="ComponentCollection"/>.
+    /// </summary>
+    public class ComponentCollectionBuilder : OrderedCollectionBuilderBase<ComponentCollectionBuilder, ComponentCollection, IComponent>
+    {
+        private const int LogThresholdMilliseconds = 100;
+
+        private IProfilingLogger _logger;
+
+        public ComponentCollectionBuilder()
+        { }
+
+        protected override ComponentCollectionBuilder This => this;
+
+        protected override IEnumerable<IComponent> CreateItems(IFactory factory)
+        {
+            _logger = factory.GetInstance<IProfilingLogger>();
+
+            using (_logger.DebugDuration<ComponentCollectionBuilder>($"Creating components. (log when >{LogThresholdMilliseconds}ms)", "Created."))
+            {
+                return base.CreateItems(factory);
+            }
+        }
+
+        protected override IComponent CreateItem(IFactory factory, Type itemType)
+        {
+            using (_logger.DebugDuration<Composers>($"Creating {itemType.FullName}.", $"Created {itemType.FullName}.", thresholdMilliseconds: LogThresholdMilliseconds))
+            {
+                return base.CreateItem(factory, itemType);
+            }
+        }
+    }
+}
@@ -0,0 +1,20 @@
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Provides a base class for composers which compose a component.
+    /// </summary>
+    /// <typeparam name="TComponent">The type of the component</typeparam>
+    public abstract class ComponentComposer<TComponent> : IComposer
+        where TComponent : IComponent
+    {
+        /// <inheritdoc />
+        public virtual void Compose(Composition composition)
+        {
+            composition.Components().Append<TComponent>();
+        }
+
+        // note: thanks to this class, a component that does not compose anything can be
+        // registered with one line:
+        // public class MyComponentComposer : ComponentComposer<MyComponent> { }
+    }
+}
@@ -0,0 +1,59 @@
+using System;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Indicates that a composer requires another composer.
+    /// </summary>
+    /// <remarks>
+    /// <para>This attribute is *not* inherited. This means that a composer class inheriting from
+    /// another composer class does *not* inherit its requirements. However, the runtime checks
+    /// the *interfaces* of every composer for their requirements, so requirements declared on
+    /// interfaces are inherited by every composer class implementing the interface.</para>
+    /// <para>When targeting a class, indicates a dependency on the composer which must be enabled,
+    /// unless the requirement has explicitly been declared as weak (and then, only if the composer
+    /// is enabled).</para>
+    /// <para>When targeting an interface, indicates a dependency on enabled composers implementing
+    /// the interface. It could be no composer at all, unless the requirement has explicitly been
+    /// declared as strong (and at least one composer must be enabled).</para>
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, AllowMultiple = true, Inherited = false)]
+    public sealed class ComposeAfterAttribute : Attribute
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ComposeAfterAttribute"/> class.
+        /// </summary>
+        /// <param name="requiredType">The type of the required composer.</param>
+        public ComposeAfterAttribute(Type requiredType)
+        {
+            if (typeof(IComposer).IsAssignableFrom(requiredType) == false)
+                throw new ArgumentException($"Type {requiredType.FullName} is invalid here because it does not implement {typeof(IComposer).FullName}.");
+            RequiredType = requiredType;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ComposeAfterAttribute"/> class.
+        /// </summary>
+        /// <param name="requiredType">The type of the required composer.</param>
+        /// <param name="weak">A value indicating whether the requirement is weak.</param>
+        public ComposeAfterAttribute(Type requiredType, bool weak)
+            : this(requiredType)
+        {
+            Weak = weak;
+        }
+
+        /// <summary>
+        /// Gets the required type.
+        /// </summary>
+        public Type RequiredType { get; }
+
+        /// <summary>
+        /// Gets a value indicating whether the requirement is weak.
+        /// </summary>
+        /// <remarks>Returns <c>true</c> if the requirement is weak (requires the other composer if it
+        /// is enabled), <c>false</c> if the requirement is strong (requires the other composer to be
+        /// enabled), and <c>null</c> if unspecified, in which case it is strong for classes and weak for
+        /// interfaces.</remarks>
+        public bool? Weak { get; }
+    }
+}
@@ -0,0 +1,40 @@
+using System;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Indicates that a component is required by another composer.
+    /// </summary>
+    /// <remarks>
+    /// <para>This attribute is *not* inherited. This means that a composer class inheriting from
+    /// another composer class does *not* inherit its requirements. However, the runtime checks
+    /// the *interfaces* of every composer for their requirements, so requirements declared on
+    /// interfaces are inherited by every composer class implementing the interface.</para>
+    /// <para>When targeting a class, indicates a dependency on the composer which must be enabled,
+    /// unless the requirement has explicitly been declared as weak (and then, only if the composer
+    /// is enabled).</para>
+    /// <para>When targeting an interface, indicates a dependency on enabled composers implementing
+    /// the interface. It could be no composer at all, unless the requirement has explicitly been
+    /// declared as strong (and at least one composer must be enabled).</para>
+    /// </remarks>
+
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, AllowMultiple = true, Inherited = false)]
+    public sealed class ComposeBeforeAttribute : Attribute
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ComposeBeforeAttribute"/> class.
+        /// </summary>
+        /// <param name="requiringType">The type of the required composer.</param>
+        public ComposeBeforeAttribute(Type requiringType)
+        {
+            if (typeof(IComposer).IsAssignableFrom(requiringType) == false)
+                throw new ArgumentException($"Type {requiringType.FullName} is invalid here because it does not implement {typeof(IComposer).FullName}.");
+            RequiringType = requiringType;
+        }
+
+        /// <summary>
+        /// Gets the required type.
+        /// </summary>
+        public Type RequiringType { get; }
+    }
+}
@@ -0,0 +1,315 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using Umbraco.Core.Collections;
+using Umbraco.Core.Logging;
+
+namespace Umbraco.Core.Components
+{
+    // note: this class is NOT thread-safe in any ways
+
+    /// <summary>
+    /// Handles the composers.
+    /// </summary>
+    public class Composers
+    {
+        private readonly Composition _composition;
+        private readonly IProfilingLogger _logger;
+        private readonly IEnumerable<Type> _composerTypes;
+
+        private const int LogThresholdMilliseconds = 100;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Composers"/> class.
+        /// </summary>
+        /// <param name="composition">The composition.</param>
+        /// <param name="composerTypes">The composer types.</param>
+        /// <param name="logger">A profiling logger.</param>
+        public Composers(Composition composition, IEnumerable<Type> composerTypes, IProfilingLogger logger)
+        {
+            _composition = composition ?? throw new ArgumentNullException(nameof(composition));
+            _composerTypes = composerTypes ?? throw new ArgumentNullException(nameof(composerTypes));
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        private class EnableInfo
+        {
+            public bool Enabled;
+            public int Weight = -1;
+        }
+
+        /// <summary>
+        /// Instantiates and composes the composers.
+        /// </summary>
+        public void Compose()
+        {
+            // make sure it is there
+            _composition.WithCollectionBuilder<ComponentCollectionBuilder>();
+
+            IEnumerable<Type> orderedComposerTypes;
+
+            using (_logger.DebugDuration<Composers>("Preparing composer types.", "Prepared composer types."))
+            {
+                orderedComposerTypes = PrepareComposerTypes();
+            }
+
+            var composers = InstantiateComposers(orderedComposerTypes);
+
+            using (_logger.DebugDuration<Composers>($"Composing composers. (log when >{LogThresholdMilliseconds}ms)", "Composed composers."))
+            {
+                foreach (var composer in composers)
+                {
+                    var componentType = composer.GetType();
+                    using (_logger.DebugDuration<Composers>($"Composing {componentType.FullName}.", $"Composed {componentType.FullName}.", thresholdMilliseconds: LogThresholdMilliseconds))
+                    {
+                        composer.Compose(_composition);
+                    }
+                }
+            }
+        }
+
+        private IEnumerable<Type> PrepareComposerTypes()
+        {
+            // create a list, remove those that cannot be enabled due to runtime level
+            var composerTypeList = _composerTypes
+                .Where(x =>
+                {
+                    // use the min/max levels specified by the attribute if any
+                    // otherwise, min: user composers are Run, anything else is Unknown (always run)
+                    //            max: everything is Run (always run)
+                    var attr = x.GetCustomAttribute<RuntimeLevelAttribute>();
+                    var minLevel = attr?.MinLevel ?? (x.Implements<IUserComposer>() ? RuntimeLevel.Run : RuntimeLevel.Unknown);
+                    var maxLevel = attr?.MaxLevel ?? RuntimeLevel.Run;
+                    return _composition.RuntimeState.Level >= minLevel && _composition.RuntimeState.Level <= maxLevel;
+                })
+                .ToList();
+
+            // enable or disable composers
+            EnableDisableComposers(composerTypeList);
+
+            // sort the composers according to their dependencies
+            var requirements = new Dictionary<Type, List<Type>>();
+            foreach (var type in composerTypeList) requirements[type] = null;
+            foreach (var type in composerTypeList)
+            {
+                GatherRequirementsFromRequireAttribute(type, composerTypeList, requirements);
+                GatherRequirementsFromRequiredByAttribute(type, composerTypeList, requirements);
+            }
+
+            // only for debugging, this is verbose
+            //_logger.Debug<Composers>(GetComposersReport(requirements));
+
+            // sort composers
+            var graph = new TopoGraph<Type, KeyValuePair<Type, List<Type>>>(kvp => kvp.Key, kvp => kvp.Value);
+            graph.AddItems(requirements);
+            List<Type> sortedComposerTypes;
+            try
+            {
+                sortedComposerTypes = graph.GetSortedItems().Select(x => x.Key).ToList();
+            }
+            catch (Exception e)
+            {
+                // in case of an error, force-dump everything to log
+                _logger.Info<Composers>("Composer Report:\r\n{ComposerReport}", GetComposersReport(requirements));
+                _logger.Error<Composers>(e, "Failed to sort composers.");
+                throw;
+            }
+
+            // bit verbose but should help for troubleshooting
+            //var text = "Ordered Composers: " + Environment.NewLine + string.Join(Environment.NewLine, sortedComposerTypes) + Environment.NewLine;
+            _logger.Debug<Composers>("Ordered Composers: {SortedComposerTypes}", sortedComposerTypes);
+
+            return sortedComposerTypes;
+        }
+
+        private static string GetComposersReport(Dictionary<Type, List<Type>> requirements)
+        {
+            var text = new StringBuilder();
+            text.AppendLine("Composers & Dependencies:");
+            text.AppendLine();
+
+            foreach (var kvp in requirements)
+            {
+                var type = kvp.Key;
+
+                text.AppendLine(type.FullName);
+                foreach (var attribute in type.GetCustomAttributes<ComposeAfterAttribute>())
+                    text.AppendLine("  -> " + attribute.RequiredType + (attribute.Weak.HasValue
+                        ? (attribute.Weak.Value ? " (weak)" : (" (strong" + (requirements.ContainsKey(attribute.RequiredType) ? ", missing" : "") + ")"))
+                        : ""));
+                foreach (var attribute in type.GetCustomAttributes<ComposeBeforeAttribute>())
+                    text.AppendLine("  -< " + attribute.RequiringType);
+                foreach (var i in type.GetInterfaces())
+                {
+                    text.AppendLine("  : " + i.FullName);
+                    foreach (var attribute in i.GetCustomAttributes<ComposeAfterAttribute>())
+                        text.AppendLine("    -> " + attribute.RequiredType + (attribute.Weak.HasValue
+                            ? (attribute.Weak.Value ? " (weak)" : (" (strong" + (requirements.ContainsKey(attribute.RequiredType) ? ", missing" : "") + ")"))
+                            : ""));
+                    foreach (var attribute in i.GetCustomAttributes<ComposeBeforeAttribute>())
+                        text.AppendLine("    -< " + attribute.RequiringType);
+                }
+                if (kvp.Value != null)
+                    foreach (var t in kvp.Value)
+                        text.AppendLine("  = " + t);
+                text.AppendLine();
+            }
+            text.AppendLine("/");
+            text.AppendLine();
+            return text.ToString();
+        }
+
+        private static void EnableDisableComposers(ICollection<Type> types)
+        {
+            var enabled = new Dictionary<Type, EnableInfo>();
+
+            // process the enable/disable attributes
+            // these two attributes are *not* inherited and apply to *classes* only (not interfaces).
+            // remote declarations (when a composer enables/disables *another* composer)
+            // have priority over local declarations (when a composer disables itself) so that
+            // ppl can enable composers that, by default, are disabled.
+            // what happens in case of conflicting remote declarations is unspecified. more
+            // precisely, the last declaration to be processed wins, but the order of the
+            // declarations depends on the type finder and is unspecified.
+
+            void UpdateEnableInfo(Type composerType, int weight2, Dictionary<Type, EnableInfo> enabled2, bool value)
+            {
+                if (enabled.TryGetValue(composerType, out var enableInfo) == false) enableInfo = enabled2[composerType] = new EnableInfo();
+                if (enableInfo.Weight > weight2) return;
+
+                enableInfo.Enabled = value;
+                enableInfo.Weight = weight2;
+            }
+
+            var assemblies = types.Select(x => x.Assembly).Distinct();
+            foreach (var assembly in assemblies)
+            {
+                foreach (var attr in assembly.GetCustomAttributes<EnableComposerAttribute>())
+                {
+                    var type = attr.EnabledType;
+                    UpdateEnableInfo(type, 2, enabled, true);
+                }
+
+                foreach (var attr in assembly.GetCustomAttributes<DisableComposerAttribute>())
+                {
+                    var type = attr.DisabledType;
+                    UpdateEnableInfo(type, 2, enabled, false);
+                }
+            }
+
+            foreach (var composerType in types)
+            {
+                foreach (var attr in composerType.GetCustomAttributes<EnableAttribute>())
+                {
+                    var type = attr.EnabledType ?? composerType;
+                    var weight = type == composerType ? 1 : 3;
+                    UpdateEnableInfo(type, weight, enabled, true);
+                }
+
+                foreach (var attr in composerType.GetCustomAttributes<DisableAttribute>())
+                {
+                    var type = attr.DisabledType ?? composerType;
+                    var weight = type == composerType ? 1 : 3;
+                    UpdateEnableInfo(type, weight, enabled, false);
+                }
+            }
+
+            // remove composers that end up being disabled
+            foreach (var kvp in enabled.Where(x => x.Value.Enabled == false))
+                types.Remove(kvp.Key);
+        }
+
+        private static void GatherRequirementsFromRequireAttribute(Type type, ICollection<Type> types, IDictionary<Type, List<Type>> requirements)
+        {
+            // get 'require' attributes
+            // these attributes are *not* inherited because we want to "custom-inherit" for interfaces only
+            var requireAttributes = type
+                .GetInterfaces().SelectMany(x => x.GetCustomAttributes<ComposeAfterAttribute>()) // those marking interfaces
+                .Concat(type.GetCustomAttributes<ComposeAfterAttribute>()); // those marking the composer
+
+            // what happens in case of conflicting attributes (different strong/weak for same type) is not specified.
+            foreach (var attr in requireAttributes)
+            {
+                if (attr.RequiredType == type) continue; // ignore self-requirements (+ exclude in implems, below)
+
+                // requiring an interface = require any enabled composer implementing that interface
+                // unless strong, and then require at least one enabled composer implementing that interface
+                if (attr.RequiredType.IsInterface)
+                {
+                    var implems = types.Where(x => x != type && attr.RequiredType.IsAssignableFrom(x)).ToList();
+                    if (implems.Count > 0)
+                    {
+                        if (requirements[type] == null) requirements[type] = new List<Type>();
+                        requirements[type].AddRange(implems);
+                    }
+                    else if (attr.Weak == false) // if explicitly set to !weak, is strong, else is weak
+                        throw new Exception($"Broken composer dependency: {type.FullName} -> {attr.RequiredType.FullName}.");
+                }
+                // requiring a class = require that the composer is enabled
+                // unless weak, and then requires it if it is enabled
+                else
+                {
+                    if (types.Contains(attr.RequiredType))
+                    {
+                        if (requirements[type] == null) requirements[type] = new List<Type>();
+                        requirements[type].Add(attr.RequiredType);
+                    }
+                    else if (attr.Weak != true) // if not explicitly set to weak, is strong
+                        throw new Exception($"Broken composer dependency: {type.FullName} -> {attr.RequiredType.FullName}.");
+                }
+            }
+        }
+
+        private static void GatherRequirementsFromRequiredByAttribute(Type type, ICollection<Type> types, IDictionary<Type, List<Type>> requirements)
+        {
+            // get 'required' attributes
+            // these attributes are *not* inherited because we want to "custom-inherit" for interfaces only
+            var requiredAttributes = type
+                .GetInterfaces().SelectMany(x => x.GetCustomAttributes<ComposeBeforeAttribute>()) // those marking interfaces
+                .Concat(type.GetCustomAttributes<ComposeBeforeAttribute>()); // those marking the composer
+
+            foreach (var attr in requiredAttributes)
+            {
+                if (attr.RequiringType == type) continue; // ignore self-requirements (+ exclude in implems, below)
+
+                // required by an interface = by any enabled composer implementing this that interface
+                if (attr.RequiringType.IsInterface)
+                {
+                    var implems = types.Where(x => x != type && attr.RequiringType.IsAssignableFrom(x)).ToList();
+                    foreach (var implem in implems)
+                    {
+                        if (requirements[implem] == null) requirements[implem] = new List<Type>();
+                        requirements[implem].Add(type);
+                    }
+                }
+                // required by a class
+                else
+                {
+                    if (types.Contains(attr.RequiringType))
+                    {
+                        if (requirements[attr.RequiringType] == null) requirements[attr.RequiringType] = new List<Type>();
+                        requirements[attr.RequiringType].Add(type);
+                    }
+                }
+            }
+        }
+
+        private IEnumerable<IComposer> InstantiateComposers(IEnumerable<Type> types)
+        {
+            IComposer InstantiateComposer(Type type)
+            {
+                var ctor = type.GetConstructor(Array.Empty<Type>());
+                if (ctor == null)
+                    throw new InvalidOperationException($"Composer {type.FullName} does not have a parameter-less constructor.");
+                return (IComposer) ctor.Invoke(Array.Empty<object>());
+            }
+
+            using (_logger.DebugDuration<Composers>("Instantiating composers.", "Instantiated composers."))
+            {
+                return types.Select(InstantiateComposer).ToArray();
+            }
+        }
+    }
+}
@@ -1,4 +1,8 @@
-using LightInject;
+using System;
+using System.Collections.Generic;
+using Umbraco.Core.Composing;
+using Umbraco.Core.Configuration;
+using Umbraco.Core.Logging;

 namespace Umbraco.Core.Components
 {
@@ -10,28 +14,233 @@ namespace Umbraco.Core.Components
    /// avoid accessing the container. This is because everything needs to be properly registered and with
    /// the proper lifecycle. These methods will take care of it. Directly registering into the container
    /// may cause issues.</remarks>
-    public class Composition
+    public class Composition : IRegister
    {
+        private readonly Dictionary<Type, ICollectionBuilder> _builders = new Dictionary<Type, ICollectionBuilder>();
+        private readonly Dictionary<string, Action<IRegister>> _uniques = new Dictionary<string, Action<IRegister>>();
+        private readonly IRegister _register;
+
        /// <summary>
        /// Initializes a new instance of the <see cref="Composition"/> class.
        /// </summary>
-        /// <param name="container">A container.</param>
-        /// <param name="level">The runtime level.</param>
-        public Composition(IServiceContainer container, RuntimeLevel level)
+        /// <param name="register">A register.</param>
+        /// <param name="typeLoader">A type loader.</param>
+        /// <param name="logger">A logger.</param>
+        /// <param name="runtimeState">The runtime state.</param>
+        /// <param name="configs">Optional configs.</param>
+        public Composition(IRegister register, TypeLoader typeLoader, IProfilingLogger logger, IRuntimeState runtimeState, Configs configs = null)
        {
-            Container = container;
-            RuntimeLevel = level;
+            _register = register;
+            TypeLoader = typeLoader;
+            Logger = logger;
+            RuntimeState = runtimeState;
+
+            if (configs == null)
+            {
+                configs = new Configs();
+                configs.AddCoreConfigs();
+            }
+
+            Configs = configs;
+        }
+
+        #region Services
+
+        /// <summary>
+        /// Gets the logger.
+        /// </summary>
+        public IProfilingLogger Logger { get; }
+
+        /// <summary>
+        /// Gets the type loader.
+        /// </summary>
+        public TypeLoader TypeLoader { get; }
+
+        /// <summary>
+        /// Gets the runtime state.
+        /// </summary>
+        public IRuntimeState RuntimeState { get; }
+
+        /// <summary>
+        /// Gets the configurations.
+        /// </summary>
+        public Configs Configs { get; }
+
+        #endregion
+
+        #region IRegister
+
+        /// <inheritdoc />
+        public object Concrete => _register.Concrete;
+
+        /// <inheritdoc />
+        public void Register(Type serviceType, Lifetime lifetime = Lifetime.Transient)
+            => _register.Register(serviceType, lifetime);
+
+        /// <inheritdoc />
+        public void Register(Type serviceType, Type implementingType, Lifetime lifetime = Lifetime.Transient)
+            => _register.Register(serviceType, implementingType, lifetime);
+
+        /// <inheritdoc />
+        public void Register<TService>(Func<IFactory, TService> factory, Lifetime lifetime = Lifetime.Transient)
+            where TService : class
+            => _register.Register(factory, lifetime);
+
+        /// <inheritdoc />
+        public void Register(Type serviceType, object instance)
+            => _register.Register(serviceType, instance);
+
+        /// <inheritdoc />
+        public void RegisterFor<TService, TTarget>(Lifetime lifetime = Lifetime.Transient)
+            where TService : class
+            => _register.RegisterFor<TService, TTarget>(lifetime);
+
+        /// <inheritdoc />
+        public void RegisterFor<TService, TTarget>(Type implementingType, Lifetime lifetime = Lifetime.Transient)
+            where TService : class
+            => _register.RegisterFor<TService, TTarget>(implementingType, lifetime);
+
+        /// <inheritdoc />
+        public void RegisterFor<TService, TTarget>(Func<IFactory, TService> factory, Lifetime lifetime = Lifetime.Transient)
+            where TService : class
+            => _register.RegisterFor<TService, TTarget>(factory, lifetime);
+
+        /// <inheritdoc />
+        public void RegisterFor<TService, TTarget>(TService instance)
+            where TService : class
+            => _register.RegisterFor<TService, TTarget>(instance);
+
+        /// <inheritdoc />
+        public void RegisterAuto(Type serviceBaseType)
+            => _register.RegisterAuto(serviceBaseType);
+
+        /// <inheritdoc />
+        public void ConfigureForWeb()
+            => _register.ConfigureForWeb();
+
+        /// <inheritdoc />
+        public IFactory CreateFactory()
+        {
+            foreach (var onCreating in OnCreatingFactory.Values)
+                onCreating();
+
+            foreach (var unique in _uniques.Values)
+                unique(_register);
+            _uniques.Clear(); // no point keep them around
+
+            foreach (var builder in _builders.Values)
+                builder.RegisterWith(_register);
+            _builders.Clear(); // no point keep them around
+
+            Configs.RegisterWith(_register);
+
+            return _register.CreateFactory();
        }

        /// <summary>
-        /// Gets the container.
+        /// Gets a dictionary of action to execute when creating the factory.
        /// </summary>
-        /// <remarks>Use with care!</remarks>
-        public IServiceContainer Container { get; }
+        public Dictionary<string, Action> OnCreatingFactory { get; } = new Dictionary<string, Action>();
+
+        #endregion
+
+        #region Unique
+
+        private string GetUniqueName<TService>()
+            => GetUniqueName(typeof(TService));
+
+        private string GetUniqueName(Type serviceType)
+            => serviceType.FullName;
+
+        private string GetUniqueName<TService, TTarget>()
+            => GetUniqueName(typeof(TService), typeof(TTarget));
+
+        private string GetUniqueName(Type serviceType, Type targetType)
+            => serviceType.FullName + "::" + targetType.FullName;

        /// <summary>
-        /// Gets the runtime level.
+        /// Registers a unique service as its own implementation.
        /// </summary>
-        public RuntimeLevel RuntimeLevel { get; }
+        /// <remarks>Unique services have one single implementation, and a Singleton lifetime.</remarks>
+        public void RegisterUnique(Type serviceType)
+            => _uniques[GetUniqueName(serviceType)] = register => register.Register(serviceType, Lifetime.Singleton);
+
+        /// <summary>
+        /// Registers a unique service with an implementation type.
+        /// </summary>
+        /// <remarks>Unique services have one single implementation, and a Singleton lifetime.</remarks>
+        public void RegisterUnique(Type serviceType, Type implementingType)
+            => _uniques[GetUniqueName(serviceType)] = register => register.Register(serviceType, implementingType, Lifetime.Singleton);
+
+        /// <summary>
+        /// Registers a unique service with an implementation factory.
+        /// </summary>
+        /// <remarks>Unique services have one single implementation, and a Singleton lifetime.</remarks>
+        public void RegisterUnique<TService>(Func<IFactory, TService> factory)
+            where TService : class
+            => _uniques[GetUniqueName<TService>()] = register => register.Register<TService>(factory, Lifetime.Singleton);
+
+        /// <summary>
+        /// Registers a unique service with an implementing instance.
+        /// </summary>
+        /// <remarks>Unique services have one single implementation, and a Singleton lifetime.</remarks>
+        public void RegisterUnique(Type serviceType, object instance)
+            => _uniques[GetUniqueName(serviceType)] = register => register.Register(serviceType, instance);
+
+        /// <summary>
+        /// Registers a unique service for a target, as its own implementation.
+        /// </summary>
+        /// <remarks>Unique services have one single implementation, and a Singleton lifetime.</remarks>
+        public void RegisterUniqueFor<TService, TTarget>()
+            where TService : class
+            => _uniques[GetUniqueName<TService, TTarget>()] = register => register.RegisterFor<TService, TTarget>(Lifetime.Singleton);
+
+        /// <summary>
+        /// Registers a unique service for a target, with an implementing type.
+        /// </summary>
+        /// <remarks>Unique services have one single implementation, and a Singleton lifetime.</remarks>
+        public void RegisterUniqueFor<TService, TTarget>(Type implementingType)
+            where TService : class
+            => _uniques[GetUniqueName<TService, TTarget>()] = register => register.RegisterFor<TService, TTarget>(implementingType, Lifetime.Singleton);
+
+        /// <summary>
+        /// Registers a unique service for a target, with an implementation factory.
+        /// </summary>
+        /// <remarks>Unique services have one single implementation, and a Singleton lifetime.</remarks>
+        public void RegisterUniqueFor<TService, TTarget>(Func<IFactory, TService> factory)
+            where TService : class
+            => _uniques[GetUniqueName<TService, TTarget>()] = register => register.RegisterFor<TService, TTarget>(factory, Lifetime.Singleton);
+
+        /// <summary>
+        /// Registers a unique service for a target, with an implementing instance.
+        /// </summary>
+        /// <remarks>Unique services have one single implementation, and a Singleton lifetime.</remarks>
+        public void RegisterUniqueFor<TService, TTarget>(TService instance)
+            where TService : class
+            => _uniques[GetUniqueName<TService, TTarget>()] = register => register.RegisterFor<TService, TTarget>(instance);
+
+        #endregion
+
+        #region Collection Builders
+
+        /// <summary>
+        /// Gets a collection builder (and registers the collection).
+        /// </summary>
+        /// <typeparam name="TBuilder">The type of the collection builder.</typeparam>
+        /// <returns>The collection builder.</returns>
+        public TBuilder WithCollectionBuilder<TBuilder>()
+            where TBuilder: ICollectionBuilder, new()
+        {
+            var typeOfBuilder = typeof(TBuilder);
+
+            if (_builders.TryGetValue(typeOfBuilder, out var o))
+                return (TBuilder) o;
+
+            var builder = new TBuilder();
+            _builders[typeOfBuilder] = builder;
+            return builder;
+        }
+
+        #endregion
    }
 }
@@ -1,16 +1,16 @@
 using System;
-using System.Runtime.CompilerServices;
-using LightInject;
 using Umbraco.Core.Cache;
 using Umbraco.Core.Dictionary;
 using Umbraco.Core.Composing;
+using Umbraco.Core.IO;
 using Umbraco.Core.Migrations;
 using Umbraco.Core.Models.PublishedContent;
 using Umbraco.Core.Persistence.Mappers;
 using Umbraco.Core.PropertyEditors;
 using Umbraco.Core.Strings;
 using Umbraco.Core.Sync;
-using Umbraco.Core._Legacy.PackageActions;
+using Umbraco.Core.Logging.Viewer;
+using Umbraco.Core.PackageActions;

 namespace Umbraco.Core.Components
 {
@@ -19,6 +19,46 @@ namespace Umbraco.Core.Components
    /// </summary>
    public static class CompositionExtensions
    {
+        #region FileSystems
+
+        /// <summary>
+        /// Registers a filesystem.
+        /// </summary>
+        /// <typeparam name="TFileSystem">The type of the filesystem.</typeparam>
+        /// <typeparam name="TImplementing">The implementing type.</typeparam>
+        /// <param name="composition">The composition.</param>
+        /// <returns>The register.</returns>
+        public static void RegisterFileSystem<TFileSystem, TImplementing>(this Composition composition)
+            where TImplementing : FileSystemWrapper, TFileSystem
+            where TFileSystem : class
+        {
+            composition.RegisterUnique<TFileSystem>(factory =>
+            {
+                var fileSystems = factory.GetInstance<FileSystems>();
+                var supporting = factory.GetInstance<SupportingFileSystems>();
+                return fileSystems.GetFileSystem<TImplementing>(supporting.For<TFileSystem>());
+            });
+        }
+
+        /// <summary>
+        /// Registers a filesystem.
+        /// </summary>
+        /// <typeparam name="TFileSystem">The type of the filesystem.</typeparam>
+        /// <param name="composition">The composition.</param>
+        /// <returns>The register.</returns>
+        public static void RegisterFileSystem<TFileSystem>(this Composition composition)
+            where TFileSystem : FileSystemWrapper
+        {
+            composition.RegisterUnique(factory =>
+            {
+                var fileSystems = factory.GetInstance<FileSystems>();
+                var supporting = factory.GetInstance<SupportingFileSystems>();
+                return fileSystems.GetFileSystem<TFileSystem>(supporting.For<TFileSystem>());
+            });
+        }
+
+        #endregion
+
        #region Collection Builders

        /// <summary>
@@ -26,60 +66,66 @@ namespace Umbraco.Core.Components
        /// </summary>
        /// <param name="composition">The composition.</param>
        public static CacheRefresherCollectionBuilder CacheRefreshers(this Composition composition)
-            => composition.Container.GetInstance<CacheRefresherCollectionBuilder>();
+            => composition.WithCollectionBuilder<CacheRefresherCollectionBuilder>();

        /// <summary>
        /// Gets the mappers collection builder.
        /// </summary>
        /// <param name="composition">The composition.</param>
        public static MapperCollectionBuilder Mappers(this Composition composition)
-            => composition.Container.GetInstance<MapperCollectionBuilder>();
+            => composition.WithCollectionBuilder<MapperCollectionBuilder>();

        /// <summary>
        /// Gets the package actions collection builder.
        /// </summary>
        /// <param name="composition">The composition.</param>
        internal static PackageActionCollectionBuilder PackageActions(this Composition composition)
-            => composition.Container.GetInstance<PackageActionCollectionBuilder>();
+            => composition.WithCollectionBuilder<PackageActionCollectionBuilder>();

        /// <summary>
        /// Gets the data editor collection builder.
        /// </summary>
        /// <param name="composition">The composition.</param>
        public static DataEditorCollectionBuilder DataEditors(this Composition composition)
-            => composition.Container.GetInstance<DataEditorCollectionBuilder>();
+            => composition.WithCollectionBuilder<DataEditorCollectionBuilder>();

        /// <summary>
        /// Gets the property value converters collection builder.
        /// </summary>
        /// <param name="composition">The composition.</param>
        public static PropertyValueConverterCollectionBuilder PropertyValueConverters(this Composition composition)
-            => composition.Container.GetInstance<PropertyValueConverterCollectionBuilder>();
+            => composition.WithCollectionBuilder<PropertyValueConverterCollectionBuilder>();

        /// <summary>
        /// Gets the url segment providers collection builder.
        /// </summary>
        /// <param name="composition">The composition.</param>
        public static UrlSegmentProviderCollectionBuilder UrlSegmentProviders(this Composition composition)
-            => composition.Container.GetInstance<UrlSegmentProviderCollectionBuilder>();
+            => composition.WithCollectionBuilder<UrlSegmentProviderCollectionBuilder>();

        /// <summary>
        /// Gets the validators collection builder.
        /// </summary>
        /// <param name="composition">The composition.</param>
        internal static ManifestValueValidatorCollectionBuilder Validators(this Composition composition)
-            => composition.Container.GetInstance<ManifestValueValidatorCollectionBuilder>();
+            => composition.WithCollectionBuilder<ManifestValueValidatorCollectionBuilder>();

        /// <summary>
        /// Gets the post-migrations collection builder.
        /// </summary>
        /// <param name="composition">The composition.</param>
        internal static PostMigrationCollectionBuilder PostMigrations(this Composition composition)
-            => composition.Container.GetInstance<PostMigrationCollectionBuilder>();
+            => composition.WithCollectionBuilder<PostMigrationCollectionBuilder>();
+
+        /// <summary>
+        /// Gets the components collection builder.
+        /// </summary>
+        public static ComponentCollectionBuilder Components(this Composition composition)
+            => composition.WithCollectionBuilder<ComponentCollectionBuilder>();

        #endregion

-        #region Singleton
+        #region Uniques

        /// <summary>
        /// Sets the culture dictionary factory.
@@ -89,7 +135,7 @@ namespace Umbraco.Core.Components
        public static void SetCultureDictionaryFactory<T>(this Composition composition)
            where T : ICultureDictionaryFactory
        {
-            composition.Container.RegisterSingleton<ICultureDictionaryFactory, T>();
+            composition.RegisterUnique<ICultureDictionaryFactory, T>();
        }

        /// <summary>
@@ -97,9 +143,9 @@ namespace Umbraco.Core.Components
        /// </summary>
        /// <param name="composition">The composition.</param>
        /// <param name="factory">A function creating a culture dictionary factory.</param>
-        public static void SetCultureDictionaryFactory(this Composition composition, Func<IServiceFactory, ICultureDictionaryFactory> factory)
+        public static void SetCultureDictionaryFactory(this Composition composition, Func<IFactory, ICultureDictionaryFactory> factory)
        {
-            composition.Container.RegisterSingleton(factory);
+            composition.RegisterUnique(factory);
        }

        /// <summary>
@@ -109,7 +155,7 @@ namespace Umbraco.Core.Components
        /// <param name="factory">A factory.</param>
        public static void SetCultureDictionaryFactory(this Composition composition, ICultureDictionaryFactory factory)
        {
-            composition.Container.RegisterSingleton(_ => factory);
+            composition.RegisterUnique(_ => factory);
        }

        /// <summary>
@@ -120,7 +166,7 @@ namespace Umbraco.Core.Components
        public static void SetPublishedContentModelFactory<T>(this Composition composition)
            where T : IPublishedModelFactory
        {
-            composition.Container.RegisterSingleton<IPublishedModelFactory, T>();
+            composition.RegisterUnique<IPublishedModelFactory, T>();
        }

        /// <summary>
@@ -128,9 +174,9 @@ namespace Umbraco.Core.Components
        /// </summary>
        /// <param name="composition">The composition.</param>
        /// <param name="factory">A function creating a published content model factory.</param>
-        public static void SetPublishedContentModelFactory(this Composition composition, Func<IServiceFactory, IPublishedModelFactory> factory)
+        public static void SetPublishedContentModelFactory(this Composition composition, Func<IFactory, IPublishedModelFactory> factory)
        {
-            composition.Container.RegisterSingleton(factory);
+            composition.RegisterUnique(factory);
        }

        /// <summary>
@@ -140,7 +186,7 @@ namespace Umbraco.Core.Components
        /// <param name="factory">A published content model factory.</param>
        public static void SetPublishedContentModelFactory(this Composition composition, IPublishedModelFactory factory)
        {
-            composition.Container.RegisterSingleton(_ => factory);
+            composition.RegisterUnique(_ => factory);
        }

        /// <summary>
@@ -151,17 +197,17 @@ namespace Umbraco.Core.Components
        public static void SetServerRegistrar<T>(this Composition composition)
            where T : IServerRegistrar
        {
-            composition.Container.RegisterSingleton<IServerRegistrar, T>();
+            composition.RegisterUnique<IServerRegistrar, T>();
        }

        /// <summary>
        /// Sets the server registrar.
        /// </summary>
        /// <param name="composition">The composition.</param>
-        /// <param name="factory">A function creating a server registar.</param>
-        public static void SetServerRegistrar(this Composition composition, Func<IServiceFactory, IServerRegistrar> factory)
+        /// <param name="factory">A function creating a server registrar.</param>
+        public static void SetServerRegistrar(this Composition composition, Func<IFactory, IServerRegistrar> factory)
        {
-            composition.Container.RegisterSingleton(factory);
+            composition.RegisterUnique(factory);
        }

        /// <summary>
@@ -171,7 +217,7 @@ namespace Umbraco.Core.Components
        /// <param name="registrar">A server registrar.</param>
        public static void SetServerRegistrar(this Composition composition, IServerRegistrar registrar)
        {
-            composition.Container.RegisterSingleton(_ => registrar);
+            composition.RegisterUnique(_ => registrar);
        }

        /// <summary>
@@ -182,7 +228,7 @@ namespace Umbraco.Core.Components
        public static void SetServerMessenger<T>(this Composition composition)
            where T : IServerMessenger
        {
-            composition.Container.RegisterSingleton<IServerMessenger, T>();
+            composition.RegisterUnique<IServerMessenger, T>();
        }

        /// <summary>
@@ -190,9 +236,9 @@ namespace Umbraco.Core.Components
        /// </summary>
        /// <param name="composition">The composition.</param>
        /// <param name="factory">A function creating a server messenger.</param>
-        public static void SetServerMessenger(this Composition composition, Func<IServiceFactory, IServerMessenger> factory)
+        public static void SetServerMessenger(this Composition composition, Func<IFactory, IServerMessenger> factory)
        {
-            composition.Container.RegisterSingleton(factory);
+            composition.RegisterUnique(factory);
        }

        /// <summary>
@@ -202,7 +248,7 @@ namespace Umbraco.Core.Components
        /// <param name="registrar">A server messenger.</param>
        public static void SetServerMessenger(this Composition composition, IServerMessenger registrar)
        {
-            composition.Container.RegisterSingleton(_ => registrar);
+            composition.RegisterUnique(_ => registrar);
        }

        /// <summary>
@@ -213,7 +259,7 @@ namespace Umbraco.Core.Components
        public static void SetShortStringHelper<T>(this Composition composition)
            where T : IShortStringHelper
        {
-            composition.Container.RegisterSingleton<IShortStringHelper, T>();
+            composition.RegisterUnique<IShortStringHelper, T>();
        }

        /// <summary>
@@ -221,9 +267,9 @@ namespace Umbraco.Core.Components
        /// </summary>
        /// <param name="composition">The composition.</param>
        /// <param name="factory">A function creating a short string helper.</param>
-        public static void SetShortStringHelper(this Composition composition, Func<IServiceFactory, IShortStringHelper> factory)
+        public static void SetShortStringHelper(this Composition composition, Func<IFactory, IShortStringHelper> factory)
        {
-            composition.Container.RegisterSingleton(factory);
+            composition.RegisterUnique(factory);
        }

        /// <summary>
@@ -233,7 +279,54 @@ namespace Umbraco.Core.Components
        /// <param name="helper">A short string helper.</param>
        public static void SetShortStringHelper(this Composition composition, IShortStringHelper helper)
        {
-            composition.Container.RegisterSingleton(_ => helper);
+            composition.RegisterUnique(_ => helper);
+        }
+
+        /// <summary>
+        /// Sets the underlying media filesystem.
+        /// </summary>
+        /// <param name="composition">A composition.</param>
+        /// <param name="filesystemFactory">A filesystem factory.</param>
+        public static void SetMediaFileSystem(this Composition composition, Func<IFactory, IFileSystem> filesystemFactory)
+            => composition.RegisterUniqueFor<IFileSystem, IMediaFileSystem>(filesystemFactory);
+
+        /// <summary>
+        /// Sets the underlying media filesystem.
+        /// </summary>
+        /// <param name="composition">A composition.</param>
+        /// <param name="filesystemFactory">A filesystem factory.</param>
+        public static void SetMediaFileSystem(this Composition composition, Func<IFileSystem> filesystemFactory)
+            => composition.RegisterUniqueFor<IFileSystem, IMediaFileSystem>(_ => filesystemFactory());
+
+        /// <summary>
+        /// Sets the log viewer.
+        /// </summary>
+        /// <typeparam name="T">The type of the log viewer.</typeparam>
+        /// <param name="composition">The composition.</param>
+        public static void SetLogViewer<T>(this Composition composition)
+            where T : ILogViewer
+        {
+            composition.RegisterUnique<ILogViewer, T>();
+        }
+
+        /// <summary>
+        /// Sets the log viewer.
+        /// </summary>
+        /// <param name="composition">The composition.</param>
+        /// <param name="factory">A function creating a log viewer.</param>
+        public static void SetLogViewer(this Composition composition, Func<IFactory, ILogViewer> factory)
+        {
+            composition.RegisterUnique(factory);
+        }
+
+        /// <summary>
+        /// Sets the log viewer.
+        /// </summary>
+        /// <param name="composition">A composition.</param>
+        /// <param name="helper">A log viewer.</param>
+        public static void SetLogViewer(this Composition composition, ILogViewer viewer)
+        {
+            composition.RegisterUnique(_ => viewer);
        }

        #endregion
@@ -0,0 +1,37 @@
+using System;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Indicates that a composer should be disabled.
+    /// </summary>
+    /// <remarks>
+    /// <para>If a type is specified, disables the composer of that type, else disables the composer marked with the attribute.</para>
+    /// <para>This attribute is *not* inherited.</para>
+    /// <para>This attribute applies to classes only, it is not possible to enable/disable interfaces.</para>
+    /// <para>Assembly-level <see cref="DisableComposerAttribute"/> has greater priority than <see cref="DisableAttribute"/>
+    /// attribute when it is marking the composer itself, but lower priority that when it is referencing another composer.</para>
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
+    public class DisableAttribute : Attribute
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="DisableAttribute"/> class.
+        /// </summary>
+        public DisableAttribute()
+        { }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="DisableAttribute"/> class.
+        /// </summary>
+        public DisableAttribute(Type disabledType)
+        {
+            DisabledType = disabledType;
+        }
+
+        /// <summary>
+        /// Gets the disabled type, or null if it is the composer marked with the attribute.
+        /// </summary>
+        public Type DisabledType { get; }
+    }
+}
@@ -1,38 +0,0 @@
-using System;
-
-namespace Umbraco.Core.Components
-{
-    /// <summary>
-    /// Indicates that a component should be disabled.
-    /// </summary>
-    /// <remarks>
-    /// <para>If a type is specified, disables the component of that type, else disables the component marked with the attribute.</para>
-    /// <para>This attribute is *not* inherited.</para>
-    /// <para>This attribute applies to classes only, it is not possible to enable/disable interfaces.</para>
-    /// <para>If a component ends up being both enabled and disabled: attributes marking the component itself have lower priority
-    /// than attributes on *other* components, eg if a component declares itself as disabled it is possible to enable it from
-    /// another component. Anything else is unspecified.</para>
-    /// </remarks>
-    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
-    public class DisableComponentAttribute : Attribute
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="DisableComponentAttribute"/> class.
-        /// </summary>
-        public DisableComponentAttribute()
-        { }
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="DisableComponentAttribute"/> class.
-        /// </summary>
-        public DisableComponentAttribute(Type disabledType)
-        {
-            DisabledType = disabledType;
-        }
-
-        /// <summary>
-        /// Gets the disabled type, or null if it is the component marked with the attribute.
-        /// </summary>
-        public Type DisabledType { get; }
-    }
-}
@@ -0,0 +1,28 @@
+using System;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Indicates that a composer should be disabled.
+    /// </summary>
+    /// <remarks>
+    /// <para>Assembly-level <see cref="DisableComposerAttribute"/> has greater priority than <see cref="DisableAttribute"/>
+    /// attribute when it is marking the composer itself, but lower priority that when it is referencing another composer.</para>
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true, Inherited = false)]
+    public class DisableComposerAttribute : Attribute
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="DisableComposerAttribute"/> class.
+        /// </summary>
+        public DisableComposerAttribute(Type disabledType)
+        {
+            DisabledType = disabledType;
+        }
+
+        /// <summary>
+        /// Gets the disabled type, or null if it is the composer marked with the attribute.
+        /// </summary>
+        public Type DisabledType { get; }
+    }
+}
@@ -0,0 +1,37 @@
+using System;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Indicates that a composer should be enabled.
+    /// </summary>
+    /// <remarks>
+    /// <para>If a type is specified, enables the composer of that type, else enables the composer marked with the attribute.</para>
+    /// <para>This attribute is *not* inherited.</para>
+    /// <para>This attribute applies to classes only, it is not possible to enable/disable interfaces.</para>
+    /// <para>Assembly-level <see cref="DisableComposerAttribute"/> has greater priority than <see cref="DisableAttribute"/>
+    /// attribute when it is marking the composer itself, but lower priority that when it is referencing another composer.</para>
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
+    public class EnableAttribute : Attribute
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="EnableAttribute"/> class.
+        /// </summary>
+        public EnableAttribute()
+        { }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="EnableAttribute"/> class.
+        /// </summary>
+        public EnableAttribute(Type enabledType)
+        {
+            EnabledType = enabledType;
+        }
+
+        /// <summary>
+        /// Gets the enabled type, or null if it is the composer marked with the attribute.
+        /// </summary>
+        public Type EnabledType { get; }
+    }
+}
@@ -1,38 +0,0 @@
-using System;
-
-namespace Umbraco.Core.Components
-{
-    /// <summary>
-    /// Indicates that a component should be enabled.
-    /// </summary>
-    /// <remarks>
-    /// <para>If a type is specified, enables the component of that type, else enables the component marked with the attribute.</para>
-    /// <para>This attribute is *not* inherited.</para>
-    /// <para>This attribute applies to classes only, it is not possible to enable/disable interfaces.</para>
-    /// <para>If a component ends up being both enabled and disabled: attributes marking the component itself have lower priority
-    /// than attributes on *other* components, eg if a component declares itself as disabled it is possible to enable it from
-    /// another component. Anything else is unspecified.</para>
-    /// </remarks>
-    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
-    public class EnableComponentAttribute : Attribute
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="EnableComponentAttribute"/> class.
-        /// </summary>
-        public EnableComponentAttribute()
-        { }
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="EnableComponentAttribute"/> class.
-        /// </summary>
-        public EnableComponentAttribute(Type enabledType)
-        {
-            EnabledType = enabledType;
-        }
-
-        /// <summary>
-        /// Gets the enabled type, or null if it is the component marked with the attribute.
-        /// </summary>
-        public Type EnabledType { get; }
-    }
-}
@@ -0,0 +1,31 @@
+using System;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Indicates that a composer should be enabled.
+    /// </summary>
+    /// <remarks>
+    /// <para>If a type is specified, enables the composer of that type, else enables the composer marked with the attribute.</para>
+    /// <para>This attribute is *not* inherited.</para>
+    /// <para>This attribute applies to classes only, it is not possible to enable/disable interfaces.</para>
+    /// <para>Assembly-level <see cref="DisableComposerAttribute"/> has greater priority than <see cref="DisableAttribute"/>
+    /// attribute when it is marking the composer itself, but lower priority that when it is referencing another composer.</para>
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true, Inherited = false)]
+    public class EnableComposerAttribute : Attribute
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="EnableComposerAttribute"/> class.
+        /// </summary>
+        public EnableComposerAttribute(Type enabledType)
+        {
+            EnabledType = enabledType;
+        }
+
+        /// <summary>
+        /// Gets the enabled type, or null if it is the composer marked with the attribute.
+        /// </summary>
+        public Type EnabledType { get; }
+    }
+}
@@ -0,0 +1,25 @@
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Represents a component.
+    /// </summary>
+    /// <remarks>
+    /// <para>Components are created by DI and therefore must have a public constructor.</para>
+    /// <para>All components are terminated in reverse order when Umbraco terminates, and
+    /// disposable components are disposed.</para>
+    /// <para>The Dispose method may be invoked more than once, and components
+    /// should ensure they support this.</para>
+    /// </remarks>
+    public interface IComponent
+    {
+        /// <summary>
+        /// Initializes the component.
+        /// </summary>
+        void Initialize();
+
+        /// <summary>
+        /// Terminates the component.
+        /// </summary>
+        void Terminate();
+    }
+}
@@ -0,0 +1,16 @@
+using Umbraco.Core.Composing;
+
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Represents a composer.
+    /// </summary>
+    public interface IComposer : IDiscoverable
+    {
+        /// <summary>
+        /// Compose.
+        /// </summary>
+        /// <param name="composition"></param>
+        void Compose(Composition composition);
+    }
+}
@@ -0,0 +1,13 @@
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Represents a core <see cref="IComposer"/>.
+    /// </summary>
+    /// <remarks>
+    /// <para>All core composers are required by (compose before) all user composers,
+    /// and require (compose after) all runtime composers.</para>
+    /// </remarks>
+    [ComposeAfter(typeof(IRuntimeComposer))]
+    public interface ICoreComposer : IComposer
+    { }
+}
@@ -1,5 +0,0 @@
-namespace Umbraco.Core.Components
-{
-    public interface IRuntimeComponent : IUmbracoComponent
-    { }
-}
@@ -0,0 +1,11 @@
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Represents a runtime <see cref="IComposer"/>.
+    /// </summary>
+    /// <remarks>
+    /// <para>All runtime composers are required by (compose before) all core composers</para>
+    /// </remarks>
+    public interface IRuntimeComposer : IComposer
+    { }
+}
@@ -1,21 +0,0 @@
-using Umbraco.Core.Composing;
-
-namespace Umbraco.Core.Components
-{
-    /// <summary>
-    /// Represents an Umbraco component.
-    /// </summary>
-    public interface IUmbracoComponent : IDiscoverable
-    {
-        /// <summary>
-        /// Composes the component.
-        /// </summary>
-        /// <param name="composition">The composition.</param>
-        void Compose(Composition composition);
-
-        /// <summary>
-        /// Terminates the component.
-        /// </summary>
-        void Terminate();
-    }
-}
@@ -1,6 +0,0 @@
-namespace Umbraco.Core.Components
-{
-    [RequireComponent(typeof(IRuntimeComponent))]
-    public interface IUmbracoCoreComponent : IUmbracoComponent
-    { }
-}
@@ -1,6 +0,0 @@
-namespace Umbraco.Core.Components
-{
-    [RequireComponent(typeof(UmbracoCoreComponent))]
-    public interface IUmbracoUserComponent : IUmbracoComponent
-    { }
-}
@@ -0,0 +1,12 @@
+namespace Umbraco.Core.Components
+{
+    /// <summary>
+    /// Represents a user <see cref="IComposer"/>.
+    /// </summary>
+    /// <remarks>
+    /// <para>All user composers require (compose after) all core composers.</para>
+    /// </remarks>
+    [ComposeAfter(typeof(ICoreComposer))]
+    public interface IUserComposer : IComposer
+    { }
+}
@@ -5,16 +5,24 @@ using Umbraco.Core.Manifest;

 namespace Umbraco.Core.Components
 {
-    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
-    public class ManifestWatcherComponent : UmbracoComponentBase, IUmbracoCoreComponent
+    public sealed class ManifestWatcherComponent : IComponent
    {
+        private readonly IRuntimeState _runtimeState;
+        private readonly ILogger _logger;
+
        // if configured and in debug mode, a ManifestWatcher watches App_Plugins folders for
        // package.manifest chances and restarts the application on any change
        private ManifestWatcher _mw;

-        public void Initialize(IRuntimeState runtime, ILogger logger)
+        public ManifestWatcherComponent(IRuntimeState runtimeState, ILogger logger)
        {
-            if (runtime.Debug == false) return;
+            _runtimeState = runtimeState;
+            _logger = logger;
+        }
+
+        public void Initialize()
+        { 
+            if (_runtimeState.Debug == false) return;

            //if (ApplicationContext.Current.IsConfigured == false || GlobalSettings.DebugMode == false)
            //    return;
@@ -22,13 +30,15 @@ namespace Umbraco.Core.Components
            var appPlugins = IOHelper.MapPath("~/App_Plugins/");
            if (Directory.Exists(appPlugins) == false) return;

-            _mw = new ManifestWatcher(logger);
+            _mw = new ManifestWatcher(_logger);
            _mw.Start(Directory.GetDirectories(appPlugins));
        }

-        public override void Terminate()
+        public void Terminate()
        {
-            _mw?.Dispose();
+            if (_mw == null) return;
+
+            _mw.Dispose();
            _mw = null;
        }
    }
@@ -0,0 +1,6 @@
+namespace Umbraco.Core.Components
+{
+    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
+    public class ManifestWatcherComposer : ComponentComposer<ManifestWatcherComponent>, ICoreComposer
+    { }
+}
@@ -5,15 +5,17 @@ using Umbraco.Core.Services.Implement;

 namespace Umbraco.Core.Components
 {
-    //TODO: This should just exist in the content service/repo!
-    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
-    public sealed class RelateOnCopyComponent : UmbracoComponentBase, IUmbracoCoreComponent
+    // TODO: This should just exist in the content service/repo!
+    public sealed class RelateOnCopyComponent : IComponent
    {
        public void Initialize()
        {
            ContentService.Copied += ContentServiceCopied;
        }

+        public void Terminate()
+        { }
+
        private static void ContentServiceCopied(IContentService sender, Events.CopyEventArgs<IContent> e)
        {
            if (e.RelateToOriginal == false) return;
@@ -0,0 +1,6 @@
+namespace Umbraco.Core.Components
+{
+    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
+    public sealed class RelateOnCopyComposer : ComponentComposer<RelateOnCopyComponent>, ICoreComposer
+    { }
+}
@@ -7,8 +7,7 @@ using Umbraco.Core.Services.Implement;

 namespace Umbraco.Core.Components
 {
-    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
-    public sealed class RelateOnTrashComponent : UmbracoComponentBase, IUmbracoCoreComponent
+    public sealed class RelateOnTrashComponent : IComponent
    {
        public void Initialize()
        {
@@ -18,6 +17,9 @@ namespace Umbraco.Core.Components
            MediaService.Trashed += MediaService_Trashed;
        }

+        public void Terminate()
+        { }
+
        private static void ContentService_Moved(IContentService sender, MoveEventArgs<IContent> e)
        {
            foreach (var item in e.MoveInfoCollection.Where(x => x.OriginalPath.Contains(Constants.System.RecycleBinContent.ToInvariantString())))
@@ -0,0 +1,6 @@
+namespace Umbraco.Core.Components
+{
+    [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
+    public sealed class RelateOnTrashComposer : ComponentComposer<RelateOnTrashComponent>, ICoreComposer
+    { }
+}
@@ -1,59 +0,0 @@
-using System;
-
-namespace Umbraco.Core.Components
-{
-    /// <summary>
-    /// Indicates that a component requires another component.
-    /// </summary>
-    /// <remarks>
-    /// <para>This attribute is *not* inherited. This means that a component class inheriting from
-    /// another component class does *not* inherit its requirements. However, the bootloader checks
-    /// the *interfaces* of every component for their requirements, so requirements declared on
-    /// interfaces are inherited by every component class implementing the interface.</para>
-    /// <para>When targetting a class, indicates a dependency on the component which must be enabled,
-    /// unless the requirement has explicitely been declared as weak (and then, only if the component
-    /// is enabled).</para>
-    /// <para>When targetting an interface, indicates a dependency on enabled components implementing
-    /// the interface. It could be no component at all, unless the requirement has explicitely been
-    /// declared as strong (and at least one component must be enabled).</para>
-    /// </remarks>
-    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, AllowMultiple = true, Inherited = false)]
-    public class RequireComponentAttribute : Attribute
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="RequireComponentAttribute"/> class.
-        /// </summary>
-        /// <param name="requiredType">The type of the required component.</param>
-        public RequireComponentAttribute(Type requiredType)
-        {
-            if (typeof(IUmbracoComponent).IsAssignableFrom(requiredType) == false)
-                throw new ArgumentException($"Type {requiredType.FullName} is invalid here because it does not implement {typeof(IUmbracoComponent).FullName}.");
-            RequiredType = requiredType;
-        }
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="RequireComponentAttribute"/> class.
-        /// </summary>
-        /// <param name="requiredType">The type of the required component.</param>
-        /// <param name="weak">A value indicating whether the requirement is weak.</param>
-        public RequireComponentAttribute(Type requiredType, bool weak)
-            : this(requiredType)
-        {
-            Weak = weak;
-        }
-
-        /// <summary>
-        /// Gets the required type.
-        /// </summary>
-        public Type RequiredType { get; }
-
-        /// <summary>
-        /// Gets a value indicating whether the requirement is weak.
-        /// </summary>
-        /// <remarks>Returns <c>true</c> if the requirement is weak (requires the other component if it
-        /// is enabled), <c>false</c> if the requirement is strong (requires the other component to be
-        /// enabled), and <c>null</c> if unspecified, in which case it is strong for classes and weak for
-        /// interfaces.</remarks>
-        public bool? Weak { get; }
-    }
-}
@@ -1,41 +0,0 @@
-using System;
-
-namespace Umbraco.Core.Components
-{
-    /// <summary>
-    /// Indicates that a component is required by another component.
-    /// </summary>
-    /// <remarks>
-    /// fixme
-    /// <para>This attribute is *not* inherited. This means that a component class inheriting from
-    /// another component class does *not* inherit its requirements. However, the bootloader checks
-    /// the *interfaces* of every component for their requirements, so requirements declared on
-    /// interfaces are inherited by every component class implementing the interface.</para>
-    /// <para>When targetting a class, indicates a dependency on the component which must be enabled,
-    /// unless the requirement has explicitely been declared as weak (and then, only if the component
-    /// is enabled).</para>
-    /// <para>When targetting an interface, indicates a dependency on enabled components implementing
-    /// the interface. It could be no component at all, unless the requirement has explicitely been
-    /// declared as strong (and at least one component must be enabled).</para>
-    /// </remarks>
-
-    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, AllowMultiple = true, Inherited = false)]
-    public class RequiredComponentAttribute : Attribute
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="RequiredComponentAttribute"/> class.
-        /// </summary>
-        /// <param name="requiringType">The type of the required component.</param>
-        public RequiredComponentAttribute(Type requiringType)
-        {
-            if (typeof(IUmbracoComponent).IsAssignableFrom(requiringType) == false)
-                throw new ArgumentException($"Type {requiringType.FullName} is invalid here because it does not implement {typeof(IUmbracoComponent).FullName}.");
-            RequiringType = requiringType;
-        }
-
-        /// <summary>
-        /// Gets the required type.
-        /// </summary>
-        public Type RequiringType { get; }
-    }
-}
@@ -1,13 +1,22 @@
 using System;
+using Umbraco.Core.Composing;

 namespace Umbraco.Core.Components
 {
+    /// <summary>
+    /// Marks a composer to indicate a minimum and/or maximum runtime level for which the composer would compose.
+    /// </summary>
    [AttributeUsage(AttributeTargets.Class /*, AllowMultiple = false, Inherited = true*/)]
    public class RuntimeLevelAttribute : Attribute
    {
-        //public RuntimeLevelAttribute()
-        //{ }
+        /// <summary>
+        /// Gets or sets the minimum runtime level for which the composer would compose.
+        /// </summary>
+        public RuntimeLevel MinLevel { get; set; } = RuntimeLevel.Install;

-        public RuntimeLevel MinLevel { get; set; } = RuntimeLevel.Boot;
+        /// <summary>
+        /// Gets or sets the maximum runtime level for which the composer would compose.
+        /// </summary>
+        public RuntimeLevel MaxLevel { get; set; } = RuntimeLevel.Run;
    }
 }
@@ -1,16 +0,0 @@
-namespace Umbraco.Core.Components
-{
-    /// <summary>
-    /// Provides a base class for <see cref="IUmbracoComponent"/> implementations.
-    /// </summary>
-    public abstract class UmbracoComponentBase : IUmbracoComponent
-    {
-        /// <inheritdoc/>
-        public virtual void Compose(Composition composition)
-        { }
-
-        /// <inheritdoc/>
-        public virtual void Terminate()
-        { }
-    }
-}
@@ -1,9 +0,0 @@
-namespace Umbraco.Core.Components
-{
-    // the UmbracoCoreComponent requires all IUmbracoCoreComponent
-    // all user-level components should require the UmbracoCoreComponent
-
-    [RequireComponent(typeof(IUmbracoCoreComponent))]
-    public class UmbracoCoreComponent : UmbracoComponentBase
-    { }
-}
@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Linq.Expressions;
-using LightInject;

 namespace Umbraco.Core.Composing
 {
@@ -14,69 +12,34 @@ namespace Umbraco.Core.Composing
    /// <typeparam name="TItem">The type of the items.</typeparam>
    public abstract class CollectionBuilderBase<TBuilder, TCollection, TItem> : ICollectionBuilder<TCollection, TItem>
        where TBuilder: CollectionBuilderBase<TBuilder, TCollection, TItem>
-        where TCollection : IBuilderCollection<TItem>
+        where TCollection : class, IBuilderCollection<TItem>
    {
        private readonly List<Type> _types = new List<Type>();
        private readonly object _locker = new object();
-        private Func<IEnumerable<TItem>, TCollection> _collectionCtor;
-        private ServiceRegistration[] _registrations;
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="CollectionBuilderBase{TBuilder, TCollection,TItem}"/>
-        /// class with a service container.
-        /// </summary>
-        /// <param name="container">A service container.</param>
-        protected CollectionBuilderBase(IServiceContainer container)
-        {
-            Container = container;
-            // ReSharper disable once DoNotCallOverridableMethodsInConstructor
-            Initialize();
-        }
-
-        /// <summary>
-        /// Gets the service container.
-        /// </summary>
-        protected IServiceContainer Container { get; }
+        private Type[] _registeredTypes;

        /// <summary>
        /// Gets the internal list of types as an IEnumerable (immutable).
        /// </summary>
        public IEnumerable<Type> GetTypes() => _types;

-        /// <summary>
-        /// Initializes a new instance of the builder.
-        /// </summary>
-        /// <remarks>This is called by the constructor and, by default, registers the
-        /// collection automatically.</remarks>
-        protected virtual void Initialize()
+        /// <inheritdoc />
+        public virtual void RegisterWith(IRegister register)
        {
-            // compile the auto-collection constructor
-            var argType = typeof(IEnumerable<TItem>);
-            var ctorArgTypes = new[] { argType };
-            var constructor = typeof(TCollection).GetConstructor(ctorArgTypes);
-            if (constructor != null)
-            {
-                var exprArg = Expression.Parameter(argType, "items");
-                var exprNew = Expression.New(constructor, exprArg);
-                var expr = Expression.Lambda<Func<IEnumerable<TItem>, TCollection>>(exprNew, exprArg);
-                _collectionCtor = expr.Compile();
-            }
-            // else _collectionCtor remains null, assuming CreateCollection has been overriden
-
-            // we just don't want to support re-registering collections here
-            var registration = Container.GetAvailableService<TCollection>();
-            if (registration != null)
-                throw new InvalidOperationException("Collection builders cannot be registered once the collection itself has been registered.");
+            if (_registeredTypes != null)
+                throw new InvalidOperationException("This builder has already been registered.");

            // register the collection
-            Container.Register(_ => CreateCollection(), CollectionLifetime);
+            register.Register(CreateCollection, CollectionLifetime);
+
+            // register the types
+            RegisterTypes(register);
        }

        /// <summary>
        /// Gets the collection lifetime.
        /// </summary>
-        /// <remarks>Return null for transient collections.</remarks>
-        protected virtual ILifetime CollectionLifetime => new PerContainerLifetime();
+        protected virtual Lifetime CollectionLifetime => Lifetime.Singleton;

        /// <summary>
        /// Configures the internal list of types.
@@ -87,8 +50,8 @@ namespace Umbraco.Core.Composing
        {
            lock (_locker)
            {
-                if (_registrations != null)
-                    throw new InvalidOperationException("Cannot configure a collection builder after its types have been resolved.");
+                if (_registeredTypes != null)
+                    throw new InvalidOperationException("Cannot configure a collection builder after it has been registered.");
                action(_types);
            }
        }
@@ -104,55 +67,54 @@ namespace Umbraco.Core.Composing
            return types;
        }

-        private void RegisterTypes()
+        private void RegisterTypes(IRegister register)
        {
            lock (_locker)
            {
-                if (_registrations != null) return;
+                if (_registeredTypes != null) return;

                var types = GetRegisteringTypes(_types).ToArray();
+
+                // ensure they are safe
                foreach (var type in types)
                    EnsureType(type, "register");

-                var prefix = GetType().FullName + "_";
-                var i = 0;
+                // register them
                foreach (var type in types)
-                {
-                    var name = $"{prefix}{i++:00000}";
-                    Container.Register(typeof(TItem), type, name);
-                }
+                    register.Register(type);

-                _registrations = Container.AvailableServices
-                    .Where(x => x.ServiceName.StartsWith(prefix))
-                    .OrderBy(x => x.ServiceName)
-                    .ToArray();
+                _registeredTypes = types;
            }
        }

        /// <summary>
        /// Creates the collection items.
        /// </summary>
-        /// <param name="args">The arguments.</param>
        /// <returns>The collection items.</returns>
-        protected virtual IEnumerable<TItem> CreateItems(params object[] args)
+        protected virtual IEnumerable<TItem> CreateItems(IFactory factory)
        {
-            RegisterTypes(); // will do it only once
+            if (_registeredTypes == null)
+                throw new InvalidOperationException("Cannot create items before the collection builder has been registered.");

-            var type = typeof (TItem);
-            return _registrations
-                .Select(x => (TItem) Container.GetInstanceOrThrow(type, x.ServiceName, x.ImplementingType, args))
+            return _registeredTypes // respect order
+                .Select(x => CreateItem(factory, x))
                .ToArray(); // safe
        }

+        /// <summary>
+        /// Creates a collection item.
+        /// </summary>
+        protected virtual TItem CreateItem(IFactory factory, Type itemType)
+            => (TItem) factory.GetInstance(itemType);
+
        /// <summary>
        /// Creates a collection.
        /// </summary>
        /// <returns>A collection.</returns>
        /// <remarks>Creates a new collection each time it is invoked.</remarks>
-        public virtual TCollection CreateCollection()
+        public virtual TCollection CreateCollection(IFactory factory)
        {
-            if (_collectionCtor == null) throw new InvalidOperationException("Collection auto-creation is not possible.");
-            return _collectionCtor(CreateItems());
+            return factory.CreateInstance<TCollection>(CreateItems(factory));
        }

        protected Type EnsureType(Type type, string action)
--- a/Show More
+++ b/Show More