WP and Legal stuff have some great legal resources specific to the WordPress community, and this week they published a post highlighting the issues surrounding how people try to resell existing GPL based plugins. Some high profile WordPress companies were interviewed such as Elegant Themes, WPMU DEV, and WooThemes.
Some takeaways are the important of trademarks, split licensing and the freedoms of the GPL. It’s a great read, which show the positives and drawbacks to using the GPL from some real world companies. It’s also great because it aims to answer some of the communities burning questions around the GPL and selling/reselling commercial products.
Give it a read here -> http://wpandlegalstuff.com/readers-ask-about-reselling-commercial-plugins/