Comment by barrkel

Cygwin implements a POSIX API on Win32 with a smattering of Nt* calls to improve compatibility but there's a lot of hoop jumping and hackery to get the right semantics. Fork isn't copy on write, for one thing.

I was a Cygwin user from about 1999 to 2022 or so, spent a little time on wsl2 (and it's what I still use on my laptop) but I'm fully Linux on the desktop since last year.