Source : Free On-Line Dictionary of Computing

Multiple Virtual Storage
     
         (MVS) Release 2 of {OS/VS2}, called MVS
        because it had multiple 16 MB virtual address spaces, in
        contrast to {SVS}.  MVS ran on the {IBM 390} series
        {mainframes}.  It became MVS/SP, then MVS/XA (with 31-bit
        addressing) and then MVS/ESA.
     
        MVS/Open Edition (MVS/OE), aimed at the growing {open systems}
        market, added {TCP/IP} and {Unix} support in an MVS address
        space, allowing users to run IBM, {CICS}-type applications,
        {batch} applications and Unix.
     
        MVS/ESA was repackaged as {OS/390} as a marketing exercise but
        it's basically the same thing.
     
        Version: 5.1.
     
        [Features?  Dates?]
     
        (1999-01-20)