OS/360 and successors

OS/360, officially known as IBM System/360 Operating System,[1][2] is a discontinued batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was influenced by the earlier IBSYS/IBJOB and Input/Output Control System (IOCS) packages for the IBM 7090/7094[citation needed] and even more so by the PR155 Operating System for the IBM 1410/7010 processors.[citation needed] It was one of the earliest[NB 1] operating systems to require the computer hardware to include at least one direct access storage device.

Although OS/360 itself was discontinued, successor operating systems, including the virtual storage MVS and the 64-bit z/OS, are still run as of 2020 and maintain application-level compatibility.