OpenStreetMap license

OpenStreetMap data is licensed under ODbL, an open source license, and therefore gives the four basic freedoms. However, it has two important conditions. The first one is obligatory attribution, while the second one is a share-alike condition. If we use OpenStreetMap data in our work, we must share the OSM part under an ODbL-compatible open source license.

ODbL differentiates three kind of products: collective database, derived database, and produced work. If we create a collective database (a database which has an OSM part), the share-alike policy only applies on the OSM part. If we create a derived database (make modifications to the OSM database), we must make the whole thing open source. If we create a map, a game, or any other work based on the OSM database, we can use any license we would like to. However, if we modify the OSM database during the process, we must make the modifications open source.