Unix System Laboratories (USL), sometimes written UNIX System Laboratories to follow relevant trademark guidelines of the time, was an American software laboratory and product development company that existed from 1989 through 1993. At first wholly, and then majority, owned by AT&T, it was responsible for the development and maintenance of one of the main branches of the Unix operating system, the UNIX System V Release 4 source code product. Through Univel, a partnership with Novell, it was also responsible for the development and production of the UnixWare packaged operating system for Intel architecture. In addition it developed Tuxedo, a transaction processing monitor, and was responsible for certain products related to the C++ programming language. USL was based in Summit, New Jersey, and its CEOs were Larry Dooling followed by Roel Pieper. Created from earlier AT&T entities, USL was, as industry writer Christopher Negus has observed, the culmination of AT&T's long involvement in Unix, "a jewel that couldn't quite find a home or a way to make a profit." USL was sold to Novell in 1993. Origins as subsidiary of AT&T AT&T announced the creation of the UNIX Software Operation (USO) – a separate and distinct AT&T business unit responsible for the development, marketing, and licensing of UNIX System V software – in January 1989. This was done, as a subsequent press release stated, "in order to separate AT&T's UNIX System source code business from its computer systems business," the latter a reference to AT&T Computer Systems. USO included the AT&T Data Systems Group organizations responsible for UNIX product planning and management, licensing, and marketing. Peter J. Weinberger was named chief scientist of USO while also retaining his job in the computing science research center at Bell Labs; no other Bell Labs assets were transferred to USO. The head of USO was Larry Dooling, who had been a vice-president in sales and marketing in the AT&T Data Systems Group. Unlike the original Unix work, which had been done in the Bell Labs facility in Murray Hill, USO and the commercialization work was done a few miles away in Summit, New Jersey. This AT&T Bell Labs location was known as SF for Summit Facility. UNIX System Laboratories, Inc., came into being as a separate subsidiary of AT&T in November 1989 and was assigned all U.S.-based AT&T Unix and USO assets. However USO continued to operate as USO until June 1990, when the