SGML (standard generalized markup language) is a standard for how to specify a document markup language or tag set. Such a specification is itself a document type definition (DTD).

Still, SGML was largely unknown until 1990, when Tim Berners-Lee, inventor of the World Wide Web, created Hypertext Markup Language as a subset of SGML.

HyperText Markup Language (HTML) is based on the SGML (Standard Generalized Markup Language) metalanguage and is the format of the World Wide Web documents. An HTML page is a simple file containing ...

IT professionals need at least a nodding acquaintance with the major markup languages, so here is a quick guide: Standard Generalized Markup Language (SGML) is the granddaddy of markup languages.