Microsoft Announced New AppModel Concepts

The new features include Sparse Package registration, Package ‘External Location’, Win32 type RuntimeBehavior, and Activation via CreateProcess to provide Win32 app with deeper integration into the OS.

Recently, Microsoft announced new AppModel concepts to provide Win32 app with deeper integration into the OS.
 
These new features - Sparse Package registration, Package ‘External Location’, Win32 type RuntimeBehavior, and Activation via CreateProcess - have been launched with Windows Build 10.0.19000.0.
 
Microsoft said that these features are the foundation for non-packaged Win32 processes to use the company's latest APIs and features.
 
Interestingly, a ‘Sparse’ Package includes an AppxManifest.xml but unlike a regular/full package, here the manifest can reference files outside its package in a predetermined ‘external location’. This enables applications(that are not able to adopt complete MSIX packaging) to gain Identity, configure state as required by UWP APIs and then take advantage of these APIs. 
  1. <Package  
  2.  xmlns:uap10="http://schemas.microsoft.com/appx/manifest/uap/windows10/10"  
  3.  IgnorableNamespaces="uap10">  
  4.   <Identity Name="PhotoStoreDemo" Publisher="CN=Contoso" ... />  
  5.   <Properties>  
  6.    ...  
  7.     <Logo>Assets\storelogo.png</Logo>  
  8.     <uap10:AllowExternalContent>true</uap10:AllowExternalContent>  
  9.   </Properties>  
  10.   <Dependencies>  
  11.     <TargetDeviceFamily Name="Windows.Desktop"  
  12.      MinVersion="10.0.19000.0"  
  13.      MaxVersionTested="10.0.19000.0" />  
  14.   </Dependencies>  
  15.   <Capabilities>  
  16.     <rescap:Capability Name="runFullTrust" />  
  17.     <rescap:Capability Name="unvirtualizedResources"/>  
  18.   </Capabilities>  
  19. ...  
  20.   <Applications>  
  21.     <Application Id="PhotoStoreDemo"  
  22.     Executable="PhotoStoreDemo.exe"  
  23.     uap10:TrustLevel="mediumIL"  
  24.     uap10:RuntimeBehavior="win32App">   
  25.      ...  
  26.     </Application>  
  27.   </Applications>  
  28. </Package>  
Source: Microsoft
 
And, in order to support a Sparse Package, a package definition now has a new <allowExternalContent> element. It enables your package AppxManifest.xml to reference content outside its package, in a specific location on disk.
 
Win32 type RuntimeBehavior - In order to help you with the compatibility of your existing Win32 app when using a Sparse Package, the app can register to have its application process be run like a non-packaged Win32 app as much as possible.
 
Microsoft said that to support Sparse Packages with an External Location, it now leverages the classic Win32 application.manifest to provide Identity in CreateProcess() scenarios.
 
Note that Microsoft also clarified that these are still new and somewhat advanced development features that do not yet have full Visual Studio integration.
 
To get full details of new features, visit the official announcement here.