DAC-1, for Design Augmented by Computer, was one of the earliest graphical computer aided design systems. Developed by General Motors, IBM was brought in as a partner in 1960 and the two developed the system and released it to production in 1963. It was publicly unveiled at the Fall Joint Computer Conference in Detroit 1964. GM used the DAC system, continually modified, into the 1970s when it was succeeded by CADANCE.