has clause is compatible license of Source code available Usage unrestricted GNU Project Free License Type Copyleft GNU GPL v3 GNU GPL v2 Attribution required Open Data Commons DbCL v1.0 ODC Database Contents License (DbCL) v1.0 http://opendatacommons.org/licenses/odbl/summary/, accessed 5 July 2016; http://opendatacommons.org/licenses/dbcl/1.0/, accessed 5 July 2016. The DbCL v1.0 allows a user of the database contents to share, create and adapt the contents. You must attribute any public use of the contents, or works produced from them. For redistribution or derivative works, you must make the use of this license clear to others, and you must keep intact any notices on the original. If you publicly use any adapted version, or works produced from an adapted version, you must also offer it under the DbCL. If you redistribute the contents, or an adapted version of them, then you may use technological measures that restrict the work (such as DRM) as long as you also redistribute a version without such measures. Users of the DbCL must comply with the ODbL v1.0. Allyson Lister Distribution with notices