System Development Corporation (SDC), based in Santa Monica, California, was considered the world's first computer software company.
SDC started in 1955 as the systems engineering group for the SAGE air defense ground system at the RAND Corporation. RAND spun off the group in 1957 as a non-profit organization that provided expertise for the United States military in the design, integration, and testing of large, complex, computer-controlled systems.
SDC became for-profit in 1969. With that change, it began to offer its services to all comers rather than only to the American military.
In 1980, SDC was sold by its board of directors to Burroughs Corporation. In 1986, Burroughs merged with the Sperry Corporation to form Unisys, and SDC was folded into Unisys Defense Systems. In 1991, Unisys Defense Systems was renamed Paramax, a wholly owned subsidiary of Unisys, so that it could be spun off to reduce Unisys debt.[1] In 1995, Unisys sold Paramax to the Loral Corporation, although a small portion of it, containing some projects that has originated in SDC, remained with Unisys. In 1996 Loral sold Paramax to Lockheed Martin. In 1997, the Paramax business unit was separated from Lockheed Martin under the control of Frank Lanza (one of the original founders of Loral), and is now a subsidiary of L-3 Communications.
In the 1960s, SDC developed the timesharing system for the AN/FSQ-32 mainframe computer for ARPA. The Q-32 was one of the first systems to support both multiple users and inter-computer communications. Experiments with a dedicated modem connection to the TX-2 at MIT led to computer communication applications such as email. In the 60s, SDC also developed the JOVIAL programming language and the Time-Shared Data Management System (TDMS), a relational database management system (RDBMS). Both were commonly used in real-time military systems.