An interesting artilce on Scott Hanselman’s blog:
Exploring cross-browser math equations using MathML or LaTeX with MathJax
It seems that there are two places online that are shining examples of online Math rendering and that's MathJax and Math.StackExchange.com. MathJax is "an open source JavaScript display engine for mathematics that works in all browsers" and Math.StackOverflow.com is well, StackOverflow for Math people. What's special about Math.SO is that it's integrated MathJax's fantastic library into it's main editor.
http://www.hanselman.com/blog/ExploringCrossbrowserMathEquationsUsingMathMLOrLaTeXWithMathJax.aspx
--Geoff
Geoffrey Duke
802.656.1172 | Sr System Administrator | Enterprise Technology Services | University of Vermont