Contribute to the Maui backend for GTK and/or Qt, nothing is stopping you
Alternatively, just because you're on .NET doesn't mean you need to use Microsoft sanctioned UI toolkits, just as C++ has no "official" UI toolkit. You're free to pick up some GTK or Qt bindings if you want a native feeling and your application is already architectures correctly. Alternatively, throw Imgui at it if you just need dev tooling, or maybe try other cross platform toolkits in the ecosystem like Avalonia or Uno
With commercial applications that want to just take their existing code and have it run on Linux with only a couple lines changed, Avalonia XPF will do that
Yup, this was it for me, GitHub was actually pleasant to use, to browse, PRs were easy, branching was easy, PRs with reviews/comments/etc were a brand new concept, especially as SourceForge and Google Code were hosted only on SVN which constantly fucked up/corrupted data in my experience
The closest thing to PRs that I knew was reviewboard, and that was a bolt on to SVN, not an actual proper integration
Alternatively, just because you're on .NET doesn't mean you need to use Microsoft sanctioned UI toolkits, just as C++ has no "official" UI toolkit. You're free to pick up some GTK or Qt bindings if you want a native feeling and your application is already architectures correctly. Alternatively, throw Imgui at it if you just need dev tooling, or maybe try other cross platform toolkits in the ecosystem like Avalonia or Uno