Xamarin.Forms

There was also a GTK package for Xamarin Forms which I've used https://github.com/xamarin/Xamarin.Forms/pkgs/nuget/Xamarin.... BUT That's now officially unsupported as all of Xamarin Forms is no longer supported and the MAUI replacement doesn't cover Linux nor does that look likely (MAUI is mired deep in problems due over-ambition, failure to resource and it seems a significant push in MS to use MAUI Hybrid aka web UIs within native apps).

https://github.com/dotnet/wpf https://github.com/xamarin/Xamarin.Forms https://github.com/dotnet/winforms >There isn't a single first-party desktop GUI framework left that is actively supported and developed. This is demonstrably false...

Microsoft officielly maintains the Android/iOS/Windows plattforms in Xamarin.Forms. There are other platforms too, e.g MacOS, Tizen and GTK# which are community supported. It’s not clear whether those will continue to work in the same way as community supported platforms. https://github.com/xamarin/Xamarin.Forms/wiki/Platform-Suppo...

WinUI and UWP seem like desktop to me, plus there are plenty of other ones, https://github.com/xamarin/Xamarin.Forms/wiki/Platform-Suppo... Just like with Qt, Flutter, wxWidgets, Gtk+, Swing and JavaFX, Forms is only ugly when one cannot bother having designers on the team.

Xamarin (the code) is open source[0]. Only the bells and whistles (live code preview, integration with VS/VS4M, etc.) are closed source. I think. [0] https://github.com/xamarin/Xamarin.Forms ; https://github.com/xamarin/xamarin-android ; https://github.com/xamarin/xamarin-macios

From the roadmap linked in that blog post: Xamarin Forms Gtk# Backend - https://github.com/xamarin/Xamarin.Forms/pull/1174 It's all floating out there right now but maybe by end-of-year ("Q4 2017") there will be something solid. This uncertainty promises enough to keep people like me from evaluating alternatives.

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

yea, xamarin.forms targets UWP. and looks like there's a forms mac branch being somewhat worked on: https://github.com/xamarin/Xamarin.Forms/tree/mac

Nothing for GTK and desktop Cocoa, but they provide Xamarin.Forms for iOS/Android/WindowsPhone8/UniversalWindows: https://github.com/xamarin/Xamarin.Forms