Kqueue is quite nice. BSD is much better designed and I enjoy working with it more. Linux suffers from people doing just enough to solve their specific problem and then no more. The result is APIs are not orthogonal and follow differing styles. Sometimes they don’t even work at all (e.g. futex fds)

I admire what Linux accomplishes functionally. But it is just as ugly as win32 in my opinion. The two are really more alike in their pragmatism than they would care to admit - but mutual hatred prevents learning from each others mistakes.

I've never worked with Win32, just read about the more core bits of NT, and those seem quite nice although perhaps overgeneral. But I've always had a soft spot for oddball systems.