Virtual Machine

(operating system)   (VM) An IBM pseudo-operating system hypervisor running on IBM 370, ESA and IBM 390 architecture computers.

VM comprises CP (Control Program) and CMS (Conversational Monitor System) providing Hypervisor and personal computing environments respectively. VM became most used in the early 1980s as a Hypervisor for multiple DOS/VS and DOS/VSE systems and as IBM's internal operating system of choice. It declined rapidly following widespread adoption of the IBM PC and hardware partitioning in microcode on IBM mainframes after the IBM 3090.

VM has been known as VM/SP (System Product, the successor to CP/67), VM/XA, and currently as VM/ESA (Enterprise Systems Architecture). VM/ESA is still in used in 1999, featuring a web interface, Java, and DB2. It is still a major IBM operating system.

["History of VM"(?), Melinda Varian, Princeton University].

Last updated: 1999-10-31