About Unix

三大UNIX为:
IBM AIX, HP UNIX,SUN Solaris

UNIX,BSD,Linux被统称为×nix系统。

BSD与Linux系统的区别:
BSD is what you get when a bunch of UNIX hackers sit down to try to port a UNIX system to the PC.
Linux is what you get when a bunch of PC hackers sit down and try to write a UNIX system for the PC.