There is actually a much better but less well-known open source library in .NET: Avalonia. Look it up their gallery of apps. Avalonia is the cross platform vers

There is actually a much better but less well-known open source library in .NET: Avalonia. Look it up their gallery of apps. Avalonia is the cross platform version of Windows Presentation Foundation (WPF) libs. It is quite good for desktop apps and many commercial pieces of software uses it.