Linux is Linux. BSD is BSD Windows also has different sys calls than both Linux and BSD, that's because it's a different OS. Yes, there's POSIX in there, but

Linux is Linux. BSD is BSD Windows also has different sys calls than both Linux and BSD, that's because it's a different OS. Yes, there's POSIX in there, but generally it is its own OS and you need to treat is as such, same as Windows really.