Or how about you produce a module, I see the module, recognise that I could make it substantially better, but with a non-legligeable investment of time. I would

Or how about you produce a module, I see the module, recognise that I could make it substantially better, but with a non-legligeable investment of time. I would like to be compensated for making the software better, or I'm simply not going to bother. I, as a developer, do not have the right to develop a module of software that uses a GPLed module of software, and then sell it as closed source (to stop someone else from packaging up my work and distributing it for free). Yes, if you've released your software under the GPL, collecting money by granting access to it in exchange for money is not a feasible business model. There are other ways, though. Think along the lines of providing support. You could also sign a contract in advance, exchanging a GPL application for a mountain of cold hard cash. What threats? What do you think the GPL is? It's a threat to use legal remedies if you don't play by the rules of the GPL. Without that implicit threat, we could just ignore the GPL as a rather boring piece of irrelevant text. This is true of any contract or license. I've not heard the FSF or Stallman argue for the abolishment of contract law.