I'm thinking about releasing some software I've written and using the GPL. My question is if I release it under the GPL and say 6 months down the road I've made some new enhancements and a company wants to buy the software from me. Can I (as the author) stop using the GPL on a new release and thus sell it to someone an intellectual property (and thus discontinue making updates). In other words, does the GPL forever premit even myself from selling my own GPL'ed software? Can anyone with some copyright or law experience answer this for me? Thanks, Jason