Flexible Schema● Anyone can invent a tag and start using it. e.g. building=collapsed
Supporting Open Source Stack● Lots of free and open source software written which supports OSM ● osm2pgsql (importing OSM into PostgreSQL) ● mapnik (cartographic rendering) ● monav (routing engine and application) ● OpenLayers (web maps) ● + much much more....
Low Adoption Barrier● Existing worldwide minutely web map updates ● www.osm.org● Daily OSM extracts available for you to import into existing GIS systems ● download.cloudmade.com● Easy for new users to get started ● potlatch2
Contributing to OSM● Ground survey ● With a GPS ● Without a GPS (eg. walking papers)● Tracing aerial imagery● Providing existing data under a free licence● Editors: Potlatch2, JOSM, Merkaartor