real operating system

real operating system n.  The sort the speaker is used to.
   People from the BSDophilic 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?"  Only
   {MS-DOS} is universally considered unreal.  See {holy wars},
   {religious issues}, {proprietary}, {Get a real computer!}