MathML

MathML is an XML-based standard for representing mathematical expressions in machine to machine communications which allows websites to display mathematical symbols and equations. Unfortunately, support for MathML is still lacking in many browsers. For those browsers with support, extra fonts will need to be installed.

To test whether your browser is capable of rendering MathML you can either visit some of the pages on this site or one of the MathML demos hosted by Mozilla. In particular, there is the Mozilla MathML Start Page which also contains a screenshot of what you might be missing. For the more adventurous, there is a MathML Torture Test.

Math Fonts

To properly view pages containing MathML you will need a unicode font complete with all of the required mathematical symbols. The STIX Fonts Project has developed a comprehensive set of fonts specifically designed for mathematical material. The STIX fonts are freely available under the SIL Open Font License.

Browsers

At present, the Mozilla project and its progeny, such as Firefox, have the best built-in MathML support. I recommend downloading either the latest Firefox release or a recent nightly build. If you prefer another browser, try Seamonkey, a recent nightly build of Camino (MacOSX only), or the MathPlayer plugin for Internet Explorer (Windows only).