IIRC that support was still noticeably heavier than starting a thread. Much faster than the unix-y fork() emulation in cygwin/msys/similar, or in things more di

IIRC that support was still noticeably heavier than starting a thread. Much faster than the unix-y fork() emulation in cygwin/msys/similar, or in things more directly ported to Windows that use native fork equivalents directly, but still not closing the thread/process efficiency difference to that seen away from Windows. This performance difference was one of the reasons (though I think a minor one) that they switched to a managed VM instead of an emulation layer for WSL2.