Uno Platform is a cross-platform application framework which lets you write an application once in XAML and C#, and deploy it to any target platform.
Uno Platform's application API is compatible with Microsoft's WinUI 3 API and the older UWP application API. In fact, when your application runs on Windows, it's just an ordinary WinUI 3 (or UWP) application.
This means that existing WinUI or UWP code is compatible with the Uno Platform. Existing WinUI or UWP libraries can be recompiled for use in Uno Platform applications. A number of 3rd-party libraries have been ported to Uno Platform.
Uno Platform is pixel-perfect by design, delivering consistent visuals on every platform. At the same time, it rests upon the native UI framework on most target platforms, making it easy to integrate native views and tap into native platform features.
Learn more about how Uno works.