IRIX 6.5.21

IRIX was a operating system created by SGI (Silicon Graphics Inc) that was based off of System V Unix. In addition, this OS had additional BSD elements. It's initial release was in 1988 and was designed to on MIPS processors. IRIX machines were typically used for visual effects in the entertainment industry and in the scientific community for several years after the fall of Amiga in the early 90s.

IRIX was the OS that introduced the XFS file system, used in some Linux distributions.