Source : Free On-Line Dictionary of Computing

Multics Relational Data Store
     
         (MRDS) The first commercial {relational database},
        implemented as part of {Multics} by Jim Weeldreyer and Oris
        Friesen of {Honeywell} Phoenix in about 1977.  MRDS included a
        report writer called LINUS written by Jim Falksen.
     
        (1997-01-29)