has clause is compatible license of has website homepage Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0 This is a free software license under the definition of "free" by the GNU Project, and is compatible with version 3 of the GNU GPL. Allyson Lister http://www.gnu.org/licenses/license-list.html, accessed 12 June 2013. License without restrictions on derivatives GNU GPL Compatible License Type GNU GPL v3 Attribution required Distribution with notices