Fri. May 29th, 2020

Microsoft announces that Project Reunion unifies Win32 and UWP APIs

2 min read

Microsoft announced Project Reunion at today’s Build 2020 conference. This is a new project to simplify the development cost of the Windows 10 platform. The main method is to unify the Win32 program and UWP applications API and run it separately from the system through tools such as NuGet.

Project Reunion will provide a truly universal platform for new Windows applications that can help developers add the latest component features to their programs, regardless of whether their programs use C ++, .NET (including WPF, Windows Forms, and UWP) language development or React Native.

The first component in Project Reunion is WinUI 3, a modern UI platform that allows developers to gradually improve their C ++, WPF, and Windows Forms programming.

The second component is WebView2. Developers can embed the Chromium-based WebView component into their programs. Because the WebView2 component is separate from the system, their programs can use this component in any version of the Windows 10 system.

Project Reunion Principles


Project Reunion works in all your apps – Win32, Packaged, and UWP – and across many versions of Windows.


Project Reunion supports your app’s use of modern software libraries for UI, AI, ML, packaging, frameworks, and libraries. Language projections for C++, Rust, C#, and JavaScript expand the benefits to all your apps. Cloud-backed apps, streaming, and edge-compute apps are all great places to use Project Reunion’s capabilities.


Project Reunion ships out of band with OS releases, with regular previews. You get to incrementally adopt Project Reunion components for your existing apps and middleware libraries using NuGet.


We’re committing to engineering Project Reunion in the open on GitHub, so you have a more direct say in how the platform evolves and can even help out.