Once you open source, can you take it back?
makecheck: I am not a lawyer.But my understanding is that the copyright holders have the right to change the license.Once people contribute to the project, they, too, are copyright holders.  If a contributor does not approve of the change to the license, he or she should have the ability to remove his contributions from the product (or otherwise relinquish copyright) before it is forked.In addition, anyone is free to fork from the last "free" version, which could cause its own problems for you.  The free software community could decide that they much prefer the free version, significantly enhance that fork, and leave your commercial product looking dull and not worth the money.