Xamarin is really focused on mobile development, and in particular a large chunk of our effort is into making C# and F# great languages on both Android and iOS.

Xamarin is really focused on mobile development, and in particular a large chunk of our effort is into making C# and F# great languages on both Android and iOS. Our Forms API is a cross-mobile API to create UIs, part of a family of cross-platform APIs that allow for more code sharing across platforms (additionally we now have libraries for 2D raster graphics, 3D retained graphics, and various assorted device-specific libraries [1]). Eto and Avalonia area really APIs on top of a .NET runtime, either Xamarin or .NET, just like Forms, and they have a focus on the desktop space. I think they are great, and we fix bugs and assist those teams when possible. That said, some of our users have asked for a long time to share their mobile code on the desktop, so we have started an effort to bring Xamarin.Forms to Mac, and we will be extending this with support for WPF on Windows as well (in addition to the already supported Windows/UWP). If you want to try out our Mac support, check out this branch: https://github.com/xamarin/xamarin.forms/tree/macOS https://github.com/xamarin/xamarin.forms/tree/macOS [1] https://components.xamarin.com/ https://components.xamarin.com/