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.
USL logo as it appeared atop the headquarters building in Summit, New Jersey
Multi-part room numbers were characteristic of the AT&T heritage of the USL office in Summit
USL Europe's offices were in Ealing, London (in the building on the right side after the road bends, as seen here in 2009)
USL had a library that was connected to the full AT&T/Bell Labs research system
Unix is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.
Ken Thompson and Dennis Ritchie, principal developers of Research Unix
Photo from USENIX 1984, including Dennis Ritchie (center)
Promotional license plate by Digital Equipment Corporation, actual license plate is used by Jon Hall
HP 9000 workstation running HP-UX, a certified Unix operating system
