TeX4ht is a system for converting TeX/LaTeX/ConTeXt/etc. documents to HTML, various XML flavors, braille, etc., optionally using MathML.
TeX4ht was created by Eitan Gurari at Ohio State University. Eitan died unexpectedly in June 2009; we mourn his loss.
With the encouragement and support of Eitan's family, CV Radhakrishnan and Karl Berry are now working on the package. Any involvement by other volunteers, from bug reports to major new development, is very welcome.