Could be on-topic on http://tex.stackexchange.com depending on your actual question. We have a few hits for MathML: http://tex.stackexchange.com/search?q=mathml, so even if your question isn't on-topic you may get some hints for how to find out more.
Personally I would say that LaTeX+MathJax is currently the best solution for most of the purposes for which MathML was designed.
I wouldn't.
The irony of saying this, by the way, is that MathJaX uses MathML internally.
I would say that server-side generated MathML together with MathJaX for broken browsers is currently the best solution for most of the purposes for which MathML was designed.
]]>