[toyg]

The whole point of .NET-Core was to remove all the (largely desktop-oriented) platform-specific dependencies that tied it to Windows, so you could run server-oriented .net programs on Linux. So no, afaik you can't simply run GUI apps built with .Net on Linux desktops - that's the reason Mono wasn't simply killed, because it covers that niche (which wouldn't even exist, were it not for Mono/Xamarin's efforts back then. But I digress...). Nowadays there are a few other attempts at providing that UI layer.

[dark-star]

.net Core still has Windows Forms thoguh? At least I (for kicks) migrated one of my old .net 4.something projects to .net core and it still works and shows the classic Windows Forms GUI.

It's (of course) not portable

[snuxoll]

.Net Core on Windows has support for loading assemblies that reference COM interfaces and the win32 API, along with other things that aren’t supported elsewhere like C++/CLI.

That’s why loading System.Windows.Forms still works, it’s not part of .Net 5+, but it can still load the assemblies on Windows (they still use GDI, etc under the hood).

[Kwpolska]

System.Windows.Forms _is_ part of .NET 5+ — but only available on Windows.