posted on Aug, 2 2006 @ 02:22 AM
UNIX is the original operating system developed by AT&T and the University of California, and then licensed for a fee to companies (like Sun
Microsystems and IBM) who make changes to it creating different flavors.
Linux is a copy of UNIX and is very similar but developed as free source software by many people, after Linus Torvald created the first basic kernel
to emulate it.
MacOS is now the most used UNIX-based system since it has a BSD core (University of California/Berkeley) ever since version 10 came out, Sun is also
UNIX but based on AT&T System V and there are some other flavors such as IBM's AIX out there.
Linux has improved greatly and since it can run on generic PC hardware, it's becoming more and more used, posing a problem to companies like Sun that
have their own proprietary hardware and software that they traditionally sold at premium prices.
HTH!