also from http://www.gnu.org/philosophy/free-sw.en.html.. http://www.gnu.org/philosophy/free-sw.en.html... >Freedom 3 includes the freedom to release your mod

also from http://www.gnu.org/philosophy/free-sw.en.html.. http://www.gnu.org/philosophy/free-sw.en.html... >Freedom 3 includes the freedom to release your modified versions as free software. A free license may also permit other ways of releasing them; in other words, it does not have to be a copyleft license. However, a license that requires modified versions to be nonfree does not qualify as a free license.