This handbook provides a comprehensive look at OpenStreetMap (OSM), the web-based editable map of the world that enables people to freely view, edit, and use geographical data in a collaborative way from anywhere on the Earth. Written for novices as well as IT specialists by two experts directly involved with OSM, this guide presents an introduction to the OSM community, the data model, and the software used in the project and offers practical, hands-on advice to contributors and users of OSM geodata. Directions for accessing OSM data and rendering custom maps with Osmarender, Mapnik, and Garmin GPS devices are included, along with a discussion of licensing issues for the maps and techniques for users seeking to run their own OSM servers.