There is a GPL'd program that has some nice icons I would like to use in a project of my own. I would like to release my project under a more liberal license like Apache or BSD. After reading the GPL V3 license (a few times), I can't figure out how it applies to resources like icons. Can I use them at all? If so, must I release my new project under GPL instead of some other license? Of course, I plan to contact the original author and ask them what they had in mind and honor that intent. But what are the legal requirements for use of graphical resources from GPL'd software?