SGML

Standard Generalized Markup Language (SGML) is the root language for many other languages, such as HTML and XML. It has been around for a long time⁸ and is still is a universal tool, both platform and system independent, for describing text. SGML is rather like Latin - the language from which other languages have been derived. Like Latin, it is more difficult to use in a contemporary context than are its children. Also, there are many more tools being developed every day to do things in XML. This is not true of SGML anymore.

XML owes much of its functionality and usefulness to the lessons learned by people using SGML.