(No, TwinBasic isn’t adequate. No, a VB.NET migration isn’t feasible.)
https://github.com/dotnet/roslyn
Now I bet what you mean is the graphical part, and yes that is only partial open source.
https://learn.microsoft.com/en-us/previous-versions/visualst...
One of the .NET design ideas was exactly to have a common runtime between VB6+, J++ and C++, using COM, but the lawsuit from Sun made them pivot to something else.
https://web.archive.org/web/20190111203733/https://blogs.msd...
This idea came back as WinRT, which they completly messed up, and for me it was how .NET 1.0 should have been in first place.
https://arstechnica.com/features/2012/10/windows-8-and-winrt...
Unfortunely that ship has sailed, given how bad UWP landed.
Already enterprise approved on the MS stack.
I know HN is all startups with macbooks on local admin, but in bigger companies even devs cannot just install whatever they want.
Windows did include other BASIC-related stuff, like GW-BASIC, QBasic, and VBScript.
Also batch. aaah, I love cmd.
If you dont care about clean room then you plainly disassemble it and translate it. I live in the US where the second option might not be legal.