planetmath.org

PlanetMath is a virtual community which aims to help make mathematical knowledge more accessible. PlanetMath's content is created collaboratively: the main feature is the mathematics encyclopedia with entries written and reviewed by members. The entries are contributed under the terms of the Creative Commons By/Share-Alike License in order to preserve the rights of authors, readers and other content creators in a sensible way. We use LaTeX, the lingua franca of the worldwide mathematical community.

On February 13^th 2013, PlanetMath.org was updated to use the new software system Planetary. Some release notes are here -- please report any remaining bugs in the Planetary Bugs Forum. You can find the old Noösphere-based system on noosphere.planetmath.org.