MediaWiki (the one behind Wikipedia) uses TeXvc application
to render maths in articles. TeXvc is written in OCaml but
there is an ongoing discussion among MediaWiki developers to
replace it with a different one, even develop a replacement from the
ground up in PHP or Python.
The reason is actually lack of developers willing to maintain TeXvc.
Its sources in the repository were not touched since 2003.
If there is anybody willing to volunteer and support the TeXvc and
keep this great success story for OCaml true, please consider
a following list of issues in BugZilla:
http://bit.ly/bsSUPM
TeXvc in SVN:
http://svn.wikimedia.org/svnroot/mediawiki/trunk/phase3/math/
With best regards,
Victor