OpenStreetMap is a project which aims to provide a free world map.

Why free ?

Because today, excluding rare exceptions, the map of your country is probably owned by a company, and data, boundaries, etc... are not public.
As surprising as it may seem, in France, every one pay for the map they can't use... Because maps are done by university, and sold (under restrictions) by a public company : IGN.


What is the projet OpenStreetMap ?

• A collaborative map : Every one can edit, modify , improve the map. It's a closely approach to wikipedia focused on cartography
• A community : mapping party, decisions are voted, every one can work on different side of the project, there is wiki, irc, MUC, mailing lists...
• It's Free ! free software : you can set up a mirror. Datas are free : just download the database (gps coords, ways and node from a map, POI,...) , and do what you want. Editors are free : Obviously there is some editors for the map, JOSM, Mercaartor, Potlatch, all free.
• It's shared supplies : There is a @home client :) : Tiles@home. It provide supplies to direct render your work on a developper mirror (http://informationfreeway.org)