ASL STEM

Definition

an operating system, or family of operating systems, developed at Bell Laboratories in the early 1970s as a replacement for an earlier system called Multics. UNIX is noteworthy because, although developed by a small team of about four people, it is in many ways superior to operating systems developed by large teams at tremendous expense (e.g.,OS/360). The current version of the Macintosh operating system (MAC OS X) is based on UNIX, as is LINUX.

Source: Downing, Douglas, et al. Dictionary of Computer and Internet Terms. 10th ed. New York, 2009. Print.