V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):
VM
       Virtual Machine (IBM, OS, IBM 370, ESA, IBM 390)
V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):
VM
       Virtual Memory (OSF)
The Free On-line Dictionary of Computing (30 December 2018):
Virtual Machine
Virtual Machine/ESA
Virtual Machine/System Product
Virtual Machine/XA
VM
VM/ESA
VM/SP
VM/XA
    (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)