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Microsoft announces Project Reunion 0.8 preview at Build 2021

Microsoft Store
Microsoft Store (Image credit: Windows Central)

What you need to know

  • A new preview version of Project Reunion is now available.
  • Features support for WinUI 3, WebView2, and .NET 5 applications.
  • Includes down-level support for Windows 10 version 1809.

Microsoft has today announced a new preview version of its new Project Reunion app framework, designed to unify the development platforms across Win32 and UWP apps. Microsoft launched Project Reunion 0.5 in March, and today is releasing version 0.8 which includes down-level support for Windows 10 version 1809 and up, .NET 5 support, as well as better WinUI 3 and WebView2 support.

Project Reunion is a project that aims to make it easy for Windows app developers to use APIs across both Win32 and UWP development platforms. Microsoft's vision for Project Reunion is for it to be the go-to framework for building Windows apps going forward, minimizing the gap between Win32 and UWP apps and simply calling them all "Windows apps" instead.

A Microsoft blog post detailed the following:

With Project Reunion you get access to modern Windows technologies and new features, plus the best of existing desktop (Win32) features. You get coherent, modern interactions and UX with WinUI 3 – and great system performance and battery life for your apps. That's why we're excited to announce the Project Reunion 0.8 preview so you can create and modernize your Windows apps seamlessly for both client and cloud endpoints. You can build experiences optimized for device hardware with hassle free app discovery and management and future proofed for Arm64.

Today's preview features support for WinUI 3 and WebView2, which bring modern technologies that allow app developers to either update their apps with modern interfaces or use Microsoft Edge's rendering engine for web-based content.

Reunion 0.8 also includes support for .NET 5 applications, which includes support for Windows Presentation Foundation and Windows Forms apps. One of the great things about Project Reunion is that it's decoupled from Windows, meaning app developers can use it and target any version of Windows 10 from version 1809 and up.

Catch up on all the announcements from Build 2021

Zac Bowden
Senior Editor

Zac Bowden is a Senior Editor at Windows Central. Bringing you exclusive coverage into the world of Windows 10 on PCs, tablets, phones, and more. Also an avid collector of rare Microsoft prototype devices! Keep in touch on Twitter: @zacbowden.

8 Comments
  • This is cool. It would be great for Microsoft to work directly with the top developers to make sure they take advantage of Project Reunion, even as they (Microsoft) revamp the Microsoft Store to make it make more sense for users.
  • Here is another project name again ???
  • It would be super interesting to see data on how many apps have used Reunion. Like sure the option is there, but how many devs are actually using it? Also, why Edge team doesn't use it to make sure their browser touch text selection is the same as the OS and actually works consistently.
  • It just came out in March. Give it time. There's still many missing features.
  • another sea change....yawn...
  • I wonder how .net MAUI (new Xamarain that also supports windows desktop) fits in with these UI changes? What are they encouraging developers to embrace moving forward? Win3UI, .net MAUI, or just WebBased? again, is it just another sea change or back peddling?
  • WinUI 3 is what they're pushing for Windows-only apps. It can be a little confusing because they're using the name of their controls framework to reference these "new" types of apps.
  • MAUI uses WinUI3 on Windows. It's actually .NET unification with .NET6. If you want Windows Only then WinUI3 and if multi-platform then MAUI.