[j16sdiz]

Linux have the binfmt https://en.wikipedia.org/wiki/Binfmt_misc . It have been used to run java, windows pe or other arch binaries.

[XMPPwocky]

That's very different.

All binfmt does is allow exec() and friends to run a custom wrapper program; for example, qemu or wine.

Windows / NT subsystems (and specifically, here, picoprocesses), effectively intercept all entries into kernelmode from a particular process; when you execute a syscall instruction, the kernel invokes subsystem-specific code.