@Milan Petrovic -@Milan Petrovic - Well the GPL is very clear about how to deal with derivative works and the license is part of the software package so I really must admit that I do not see any clarification issues here. You might have interest in a discussion about the license implications this poll has on the meta-level here: "Pirated themes" - How to deal with Non-GPL Sourcecode (e.g. in Themes)