GELLMU is an acronym for “Generalized Extensible LaTeX-Like MarkUp”. With GELLMU one may use LaTeX-like markup to write consciously for SGML document types such as HTML, DocBook, TEI, or GELLMU's own LaTeX-like document type ‘article’.

The package provides a syntactic translator, which is the project layer for all document types.

The article document type is very much like LaTeX with a tightly enforced syntax and vocabulary. For article, the package provides translators to classic HTML, regular LaTeX and the XML form of HTML extended by MathML (XHTML). The latter form provides optimal online content that is ‘accessible’ and in the author's opinion superior to PDF for web presentation.