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!}