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 ODbL v1.0 Allyson Lister Open Database License (ODbL) v1.0 The ODbL v1.0 allows a user of the databases to share, create and adapt the database. You must attribute any public use of the database, or works produced from the database. For redistribution of the database or derivative works, you must make the use of this license clear to others, and you must keep intact any notices on the original database. If you publicly use any adapted version of this database, or works produced from an adapted database, you must also offer that adapted database under the ODbL. If you redistribute the database, or an adapted version of it, then you may use technological measures that restrict the work (such as DRM) as long as you also redistribute a version without such measures. http://opendatacommons.org/licenses/odbl/summary/, accessed 5 July 2016. Distribution with notices