OpenStreetMap
OpenStreetMap also known as OSM is a project that provides map data to many web sites, the data is free to use as long as it is correctly credited. Anybody can add and maintain the data at OpenStreetMap. Project-GC uses OpenStreetMap as the standard map in the map based tools. Data from OpenStreetMap, via OSM-Boundaries.com, is also the main source for administrative boundaries used to determine regions and counties at Project-GC.