Source : Free On-Line Dictionary of Computing

OS/390
     
         An {IBM} {mainframe} {operating system},
        featuring integrated {MVS}, {UNIX}, {LAN}, {distributed
        computing} and {application enablement services} through its
        base elements.  These base services enable open, distributed
        processing and offer a foundation for object-ready application
        development.  The OS/390 base includes a {Communication
        Server} that includes {VTAM}, the {VTAM AnyNet} feature,
        {TCP/IP} and {TIOC}.  It provides {SNA} ({3270}), {APPC},
        {High Performance Routing}, {ATM} support, {sockets} and
        {RPC}.
     
        OS/390 is basically rebranded, repackaged {MVS/OE}, {CMOS}
        processors, {RAMAC} disk arrays and {open systems} extension
        to networking in {VTAM}, the principle being that if you can't
        compete, rebrand what you have and tell everyone it's
        something new.
     
        {Home (http://204.146.133.206/os390/index.html)}.
     
        (1999-01-20)