IBM’s System/360 (S/360) mainframe computer family was announced fifty years ago, on 7 April 1964, and was marketed between 1965 and 1978. It was the first computer family that was designed to cover more or less completely the entire IT field, from business purposes to scientific application. The design made a clear distinction between architecture and implementation, enabling IBM to release fully compatible models at different prices and with different performance levels. The chief architect of the suite was Gene Amdahl, the project was led by Fred Brooks.

The speed of the slowest System/360 models varied in speed from 0.0018 to 0.034 MIPS; the fastest models were approximately 50 times as fast. Their internal memory ranged between 8KB p to 8MB, though the latter was quite uncommon.

The S/360 models were extremely successful in the computer market thanks to their scalability, performance and full compatibility. The design had great influence on the design and architecture of modern computers. The compatibility of applications is maintained by IBM to this day: System/360 software can be run on IBM zSeries machines without any necessary changes.