Microsoft continues to baby-step around the obvious, but it has officially deprecated the Universal Windows Platform (UWP) as it pushes the desktop-focused Windows App SDK (formerly called Project Reunion) and WinUI 3 as the future of Windows application development.
“The Windows App SDK is focused on empowering developers to build the most productive apps on Windows,” Microsoft’s Thomas Fennel explains. “To achieve this, we are using the existing desktop project types [and not UWP] as the foundation of the Windows App SDK, due to the vast amount of existing desktop APIs and compatibility that desktop project types provide.”
(Thanks to Rafael Rivera for pointing out this documentation on Twitter.)
For those unclear on the matter, the Windows App SDK basically takes key UWP technologies and new technologies like WinUI 3 that will not be backported to UWP and makes them available to developers in a way that is not tied to specific Windows releases (as was the case with individual UWP features). In this way, Microsoft can “deliver on the agility and backward compatibility developers need to reach across the entire Windows ecosystem” while not leaving developers behind.
Going forward, UWP will only receive “bug, reliability, and security fixes,” and not new features, Microsoft says, indicating that it is now deprecated. Developers with UWP apps in the market who “are happy with [the] current functionality in UWP” can of course continue to keep using UWP. But those who want “the latest runtime, language, and platform features,” including WinUI 3, WebView 2, .NET 5, full compatibility with Windows 10 version 1809 or newer, and any upcoming new features will have to migrate their apps to the Windows App SDK.
I know this is a controversial topic for some. But to reiterate the obvious, Microsoft told the press years ago, literally, that it was killing UWP. And despite its mealymouthed public non-explanations about this topic, this new information represents an official and public confirmation that it has taken the first official step towards the future of Windows app development. Which is desktop apps built with Windows App SDK, and not UWP.
The good news, of course, is that developers who invested time in learning UWP and creating UWP apps can apply their knowledge and experience to creating new Windows App SDK apps or migrating existing apps to this improved and fully supported platform. This is one of Microsoft’s greatest strengths as a platform maker, I think: its ongoing dedication to not leaving developers behind. So while UWP may be transitioning to the maintenance phase of its lifecycle, those who support it can keep moving forward. Folks, that’s good news.