Syscall ABI translations are pretty common in Unices, with Linux itself having had support for a few of them, and a lot of others (including Solaris/illumos, Fr

Syscall ABI translations are pretty common in Unices, with Linux itself having had support for a few of them, and a lot of others (including Solaris/illumos, FreeBSD, NetBSD) supporting Linux as well. The special thing about the "Linux on Windows" subsystem is just how different the host OS is, which requires Microsoft to do some quite extensive changes to the Windows kernel in order to support it. Unix to Unix is relatively easy by comparison. OTOH, we also have Wine, which is pretty much exactly the same sort of thing as Windows 10's Linux subsystem.