has clause is compatible license of Usage unrestricted GNU GPL Compatible License Type GNU GPL v3 GNU GPL v2 Mozilla Public License Version 2.0 MPL v2.0 http://www.gnu.org/licenses/license-list.html, accessed 12 June 2013; http://en.wikipedia.org/wiki/Mozilla_Public_License, accessed 12 June 2013. MPL v2.0 a free software license as defined by the GNU Project. Section 3.3 provides indirect compatibility between this license and the GNU GPL version 2.0, the GNU LGPL version 2.1, the GNU AGPL version 3.0, and all later versions of those licenses. The MPL allows covered source code to be mixed with other files under a different, even proprietary license. However, code files licensed under the MPL must remain under the MPL and freely available in source form. GNU LGPL v3 GNU AGPL v3 GNU LGPL v2.1 MPL