Source : Free On-Line Dictionary of Computing

real operating system
     
         The sort the speaker is used to.
        People from the {BSD}ophilic academic community are likely to
        issue comments like "{System V}?  Why don't you use a *real*
        operating system?", people from the commercial/industrial
        {Unix} sector are known to complain "BSD?  Why don't you use a
        *real* operating system?", and people from {IBM} object "Unix?
        Why don't you use a *real* operating system?"
     
        See {holy wars}, {religious issues}, {proprietary}, {Get a
        real computer!}.
     
        [{Jargon File}]
     
        (1997-03-12)