MathML at MIT
On this page, MathML at MIT, you will find basic information to help you get started with using MathML.

ASCIIMathML.js, Translating ASCII math notation to MathML and graphics. Requires Internet Explorer 6 + MathPlayer or Firefox/Mozilla/Netscape (with MathML fonts).

A Short Math Guide for LaTeX (PDF)

AMS-LaTeX, The software distributed under the name "AMS-LaTeX" consists of various extensions for LaTeX.

Testing Math Markup
Bob demonstrates that WikiSpaces has LaTeX capability, on his wiki at

MathParser is a freeware tool that converts MathML into LaTeX.
MathParser parses MathML to Latex, tutorial.

Markup in Microsoft Office
Microsoft Equation Editor (Wikipedia)

Math markup marked down
Blog post Math markup marked down discusses new issues that scientists and mathematicians face in using Microsoft Office.

Twitter hashtag: #mathmarkup