Source : Free On-Line Dictionary of Computing

Convergent Technologies Operating System
     
         (CTOS, BTOS, STARSYS) /see-toss/ A modular,
        {message-passing}, {multi-process} based {operating system}.
     
        {Convergent Technologies}' first product was the IWS
        (Integrated Workstation) based on the {Intel 8086}, which had
        CTOS as its operating system.  It is a modular operating
        system with built in {local area networking}.  CTOS supports
        multiple processes or {threads}, and message-based
        {inter-process communication}.
     
        Companies which have licensed CTOS include {Burroughs} (BTOS)
        and {Bull} (STARSYS).  The largest customer was {Unisys}, with
        whom Convergent Technologies merged to become one company in
        1988.  CTOS now has over 800,000 users worldwide.
     
        CTOS runs on Intel {Pentium} computers, and can run
        concurrently with {Microsoft} {Windows NT}.
     
        For some reason, CTOS is no longer marketted to new customers,
        although there is a support comittment for existing customers
        until 2001.  Major customers include Police Forces, Banks, and
        Airlines.
     
        Latest version: CTOS III 1.3.2.
     
        ["Exploring CTOS", Miller E., Crook J., Loy J. - Prentice
        Hall, ISBN 0-13-297342-1, 1991].
     
        (1996-09-24)