This package provides a converter from TeX and LaTeX to SGML-based formats such as (X)HTML, MathML, OpenDocument, and Docbook, providing a configurable (La)TeX-based authoring system for hypertext. TeX4ht does not independently parse (La)TeX source (so it avoids the difficulties encountered by many other converters, arising from the irregularity of (La)TeX syntax). Instead, TeX4ht uses (La)TeX itself (with myriad macro modifications) to produce a helper DVI file that it can then process. This technique allows TeX4ht to approach the robustness characteristic of restricted-syntax systems such as gellmu.