Last modified: 2014-03-09 11:54:23 UTC
jsmath (http://www.math.union.edu/~dpvc/jsMath/) is a javascript plugin to render TeX markup on the client side. It would be good to have an option in the TeX preferences to use jsmath for displaying formula. With this, the user would not need to download PNG images of formula, which would decrease network load and speed up loading of the page.
Now that Math is a separate extension, this should be one of the possible output types in $wgDefaultUserOptions['math']
JSMath seems to be unmaintained, and MathJax is the successor. There's already a MathJax extension (http://www.mediawiki.org/wiki/Extension:MathJax), but that also seems to be unmaintained. (And it's functionality really should be folded into this extension anyway)
See also bug 31406 comment6.
MathJax is being actively pursued now; bug 31406 and friends are successor to this.