If you examine the wiki, you will find that the POSIX layer of Windows is the first implementation. https://en.m.wikipedia.org/wiki/Windows_Subsystem_for_Linux

If you examine the wiki, you will find that the POSIX layer of Windows is the first implementation. https://en.m.wikipedia.org/wiki/Windows_Subsystem_for_Linux https://en.m.wikipedia.org/wiki/Windows_Subsystem_for_Linux I had known for some time that VAX/VMS was strikingly similar to Windows NT, but I learned a few days ago that the failed Mica project introduced a POSIX interface. https://en.m.wikipedia.org/wiki/DEC_MICA https://en.m.wikipedia.org/wiki/DEC_MICA