[nikofeyn]

none of that makes any sense. c#, f#, and vb.net all target .NET (and thus the CLR) and are interoperable. they are also cross-platform with .NET core.

and saying “most open source modern OO languages ... target the JVM” is not accurate. if you mean modern OO JVM languages, then yea, of course, but that is satisfied analogously by the .NET languages.

the c# and f# compilers, .NET core (libraries and framework), and core CLR (the runtime) are all open source and cross-platform. there isn’t anything closed about it. i don’t know what you mean by “closed microsoft bubble of open source”.

why do the .NET languages need LLVM or JVM implementations to be useful? again, that doesn’t make sense.