System z mainframe operating system usually used for smaller-scale mainframe environments. First released as Disk Operating System/360, or DOS/360 in 1966. Renamed to DOS/VS in 1972, then DOS/VSE (extended DOS/VS) in 1979. Bundled with other products required for DOS/VSE system such as VTAM and CICS in 1982 and called SSX/VSE (Small Systems Executive), later renamed to VSE/SP in 1986. Addressing expanded from 24 to 31 bits in the late 1980s, and renamed VSE/ESA. Renamed again to z/VSE in 1990.
IBM Product IDs:
Entry last updated: 02-Jan-2013