Jitse Niesen is running a modified version of MediaWiki that can
produce MathML in addition to the current support for HTML and PNG
output.
http://wiki.blahtex.org/
The test wiki installation
http://www.blahtex.org/
Blahtex home page, with source code and manual for blahtex 0.4 (the
underlying TeX-to-MathML converter), an interactive demo and samples of
equations from wikipedia
http://meta.wikimedia.org/wiki/Talk:Blahtex
Discussion page on Meta
(This message has been cross-posted at village pump (technical) and at
wikiproject mathematics on en.wikipedia.)
David Harvey