vm

from The Free On-line Dictionary of Computing (8 July 2008)

Virtual Machine
Virtual Machine/ESA
Virtual Machine/System Product
Virtual Machine/XA
VM
VM/ESA
VM/SP
VM/XA

   <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.

   (http://vmdev.gpl.ibm.com/).

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

   (1999-10-31)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

VM
       Virtual Machine (IBM, OS, IBM 370, ESA, IBM 390)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

VM
       Virtual Memory (OSF)