The Free On-line Dictionary of Computing (30 December 2018):

sgmls

    Sgmls is an SGML parser derived from the
   ARCSGML parser materials which were written by Charles
   Goldfarb.  It outputs a simple, easily parsed, line oriented,
   ASCII representation of an SGML document's Element Structure
   Information Set (see pp 588-593 of "The SGML Handbook").  It
   is intended to be used as the front end for
   structure-controlled SGML application programs.

   Version 1.1 for Unix and MS-DOS by James J. Clark
    and Charles Goldfarb.

   (ftp://ftp.uu.net/pub/text-processing/sgml/sgmls-1.0.tar.Z),
   (ftp://ftp.jclark.com/sgmls/sgmls-1.1.tar.Z).

   E-mail: James Clark .

   (1993-02-22)