Unix System Laboratories or USL was originally organized as part of Bell Labs in 1989. USL joined with the UNIX Software Operation, also a Bell Laboratories division, in 1990. It assumed responsibility for Unix development and licensing activities. It then became a separate wholly owned subsidiary, formed, owned, and operated by American Telephone and Telegraph Corporation, the parent company of Bell Labs.
In June 1993 Novell purchased USL and all of the Unix assets, including all copyrights, trademarks and licensing contracts
