Ruby has support for plenty of "exotic" systems like HP UX, AIX etc. It's unclear how many people actually use it, but it's there.
> I don't know if they want to use an existing JIT codegen like LLVM or Cranelift, or their own.
Their own.
My bad, that's really not what I understood from your initial statement. But yes agreed.
The only real downside is discussed on the ticket. Ruby is primarily installed from source, so requiring a second toolchain is not ideal.
No idea about HP-UX, it is impossible to find anything now, apparently HPE has buried almost everything about it. Completely unrelated to how good it used to be about 20 years ago.
> you wouldn't use ruby outside of Linux, Windows, Mac, FreeBSD, OpenBSD
Isn't quite true.