Mozilla
Mozilla Relicensing FAQ Version 1.0 http://www.mozilla.org/MPL/relicensing-faq.html retrieved from the original
MPL-in-GPL Developer Guidelines — Mozilla https://www.mozilla.org/en-US/MPL/2.0/combining-mpl-and-gpl/
MPL 2.0 FAQ — Mozilla https://www.mozilla.org/en-US/MPL/2.0/FAQ/
copyleft richard stallman fsf free software foundation gnu gpl freedom / prevent proprietary