VMS

VMS /V-M-S/ n.  DEC's proprietary operating system for its
   VAX minicomputer; one of the seven or so environments that loom
   largest in hacker folklore.  Many UNIX fans generously concede that
   VMS would probably be the hacker's favorite commercial OS if UNIX
   didn't exist; though true, this makes VMS fans furious.  One major
   hacker gripe with VMS concerns its slowness -- thus the following
   limerick:

        There once was a system called VMS
        Of cycles by no means abstemious.
             It's chock-full of hacks
             And runs on a VAX
        And makes my poor stomach all squeamious.
                                         -- The Great Quux

   See also {VAX}, {{TOPS-10}}, {{TOPS-20}}, {{UNIX}}, {runic}.