@ryanc my recollection is that 2000 was more limited with the windows subsystems for (unix, mac etc), while NT4 could be put in a posix-compliant mode and mostly work. Plus 2000 was when NT started to acquire more of the DOS-based-windows "cruft". But my experience with both 2000 and NT4 is super limited and my reply was mostly poking the bear.
I mostly have a hatred of windows 95/98, and vista-on, and just dislike the gui of XP.