Alt text:
meme with the 'Always has been' format
Linux, MacOS, OpenBSD and ChromeOS logos on top of the Earth
The first astronaut says 'Wait, it's all Unix?'
A Windows logo, on top of the second astronaut.
The second astronaut says 'Always has been' and points a gun to the first astronaut.
That is Windows NT personalities. It was originally able to run OS/2 stuff too. Doesn't really make NT a UNIX. Note: They used this stuff for WSLv1, but it was slow and had same issue as WINE. Swapping underlying implementation brings out bugs of the software above.