Correct, a commercialization clause is clearly incompatible with the GPL as is mentioned in their FAQ: http://www.gnu.org/licenses/gpl-faq.html#NoMilitary http:

Correct, a commercialization clause is clearly incompatible with the GPL as is mentioned in their FAQ: http://www.gnu.org/licenses/gpl-faq.html#NoMilitary http://www.gnu.org/licenses/gpl-faq.html#NoMilitary So short of proper dual-licensing (which this isn't), that clause isn't valid.