Open Street Map - Licensing

Licensing

OpenStreetMap data was originally published under a Creative Commons open content license with the intention of promoting free use and redistribution of the data. In September 2012, the license was changed to the Open Database License (ODbL) from Open Data Commons (ODC) in order to more specifically define its bearing on data rather than representation.

As part of this relicensing process, some of the map data was removed from the public distribution. This included all data contributed by members that did not agree to the new licensing terms, as well as all subsequent edits to those affected objects. It also included any data contributed based on input data that was not compatible with the new terms. Estimates suggested that over 97% of data would be retained globally, however certain regions would be affected more than others, such as in Australia where 24 to 84% of objects would be retained (depending on the type of object). Ultimately, more than 99% of the data was retained, with Australia and Poland being the countries most severely affected by the change.

All data added to the project needs to have a license compatible with the Open Database License. This can include out-of-copyright information, public domain or other licenses. Contributors agree to a set of terms which require compatibility with the current license. This may involve examining licenses for government data to establish whether they are compatible.

Software used in the production and presentation of OpenStreetMap data is available from many different projects and each may have their own licencing. The application — what users access to edit maps and view changelogs, is powered by Ruby on Rails. The application also uses PostgreSQL for storage of user data and edit metadata. The default map is rendered by Mapnik, stored in PostGIS, and powered by an Apache module called mod_tile. Certain parts of the software, such as the map editor Potlatch2, have been made available as public domain.