Xenix
Xenix is a discontinued line of Unix operating systems developed and sold by Microsoft. It was based on AT&T's Unix System V. Microsoft acquired the rights to license and distribute Unix from AT&T in 1979. Xenix was first released in 1980 for microcomputers. It was a significant step in bringing Unix to the Intel x86 architecture, which was becoming increasingly popular for business and personal computing.
Over time, Microsoft released several versions of Xenix for different hardware platforms, including the IBM PC,
In 1987, Microsoft sold its Xenix business to The Santa Cruz Operation (SCO), which continued to develop