Cheat Engine contains GPL-licensed code but disallows commercial use
Let me clear up a huge and very common misconception: an (alleged) GPL violation like this doesn't mean that you, the recipient, suddenly has the right to demand that the rest of the code be released as GPL. <i>All</i> it does is give the copyright holder of the GPL'd code a legal claim against the developer of the infringing product. It's unlikely that even the copyright holder could get a court to award anything but monetary damages. Courts are very reluctant to order specific performance (i.e. release all of your code as GPL) of a contract instead of just granting monetary damages. (Like a reply points out, the copyright holder is likely to win an injunction against further infringement.)<p>Importantly, the new code in the infringing product is still copyrighted, and that copyright is <i>owned by the person who wrote that code</i> even though they also violated the GPL license of other code.<p>Edit: Good point about the SFC/Vizio case. I would be surprised if the SFC wins, but it's a clever argument. It would be a major earthquake for the free software world, but maybe not an earthquake in their favor. No one is going to touch GPL code with a ten foot pole if it gives the entire public standing to sue you.