Source : Free On-Line Dictionary of Computing

DTSS
     
         The first commercial {time-sharing} system,
        created by {Dartmouth College} and sold by {General Electric}
        around 1967.
     
        GE's Information Service Divsion (ISD) marketed DTSS which was
        running on a system called {GE-265} (a combination of the
        {front-end processor} the {Datanet-30} and the {GE-235}).
     
        DTSS was ported (and significantly improved by GE ISD around
        1965-1966 on a combination of DN-30 and {GE-635}).  This
        proprietary system, called Mk-II, later improved by GE and
        renamed Mk-III, is still working today (1997) as part of the
        GE service bureau that also includes {IBM} and {Unix}
        computers.
     
        (1997-09-16)