Xenix is a version of the Unix operating system, licensed by Microsoft from AT&T in the late 1970s. The Santa Cruz Operation (SCO) later acquired exclusive rights to the software, and eventually began distributing it as SCO UNIX. History Xenix was Microsoft's version of Unix intended for use on microcomputers; since Microsoft wasn't able to license the "UNIX" name itself, they gave it an original name. The -ix ending follows a convention used by many other Unix-like operating systems. Microsoft… (More on Xenix)