Microsoft explains what is and isn't Project Reunion

At Build 2020, Microsoft first announced Project Reunion, a new project to make app development easier for Windows 10 platform. Project Reunion unifies access to existing Win32 (legacy Windows API) and UWP (Universal Windows Platform) APIs and makes them available decoupled from the OS, via tools like NuGet. Apps built using Project Reunion components can work across all the Windows 10 versions and devices.

Microsoft’s explanation of Project Reunion was not clear to many developers. Developers had doubts about whether Project Reunion is an application model like UWP or is it a new packaging or isolation model. Recently, Microsoft has updated the GitHub page of Project Reunion with clear details.

What Project Reunion Isn’t:

• Project Reunion isn’t a new application model or platform from Windows. There won’t be a “new Project Reunion App” template for Visual Studio, VSCode, or other development environments.
  You’ll still have full access to the Windows SDK and associated kits. Over time the features that Project Reunion provides will grow beyond just merging the existing Win32 and UWP models and provide additional functionality for all apps to use.
• Project Reunion isn’t a new packaging or isolation model for applications. There won’t be required changes to your application in order to access Project Reunion functionality other than using the new functionality itself. If the APIs you use need identity or packaging these requirements will be indicated.
• Project Reunion isn’t a new security or privacy model for applications. Your app’s existing security, privacy, reliability, and identity stories continue to work with Project Reunion. There may be places that Project Reunion helps your app be more aware of customer security or privacy concerns. Project Reunion helps you use modern security & privacy functionality that evolves alongside your application’s needs.
• Project Reunion isn’t a way to run your app in the cloud. Using Project Reunion technology will help get your app on modern API families that are cloud ready. Key components like modern lifecycle and state isolation help get your app ready to run wherever your customers are.

What Project Reunion is:

• Project Reunion is a set of libraries, frameworks, components, and tools that you can use in your apps to access powerful Windows platform functionality from all kinds of apps on many versions of Windows. Project Reunion combines the powers of Win32 native applications alongside modern API usage techniques, so your apps light up everywhere your users are.
• Your app can use the parts of Project Reunion that are most interesting to you without having to rewrite it into a new app model or deployment system. Project Reunion provides a single consistent API surface for both new and existing functionality that automatically adapts to your preferred app model and deployment mechanism.

In the future, Microsoft will deliver new Windows functionality as part of the Project Reunion Family so that developers can take advantage of it in their applications.

Following Project Reunion Family Components are available now:

• WinUI 3 for XAML
• C++/WinRT, RUST/WinRT, and C#/WinRT
• MSIX-Core

Following Project Reunion Family Components will be available in the future:

• Edge/Chromium backed WebView2
• Modern Lifecycle helpers
• Startup Tasks
• Update Scan Integration
• Access to user resources
• Modern Resource Tooling

You can learn more about Project Reunion from the source link below.

Source: Microsoft via: Rafael