Unix, along with Linux and Windows, is one of the most widely-used and oldest operating systems in the world. Since it operates on every hardware platform imaginable, Unix is used to running just about any type of software application you can think of. Banking applications, web servers, videogames and research stations are just a few possible uses for this diverse OS. Since Unix code was originally distributed freely among universities, government institutions and research laboratories, Unix is considered to be the first open-source operating system. Some open-source permutations of Unix are FreeBSD, OpenBSD, Darwin, and Linux. Some commercial distributions of Unix are SCO, Solaris, and AIX.