| There is nothing wrong with dual licensing, even RMS has said: "I've considered selling exceptions acceptable since the 1990s, and on occasion I've suggested it to companies. Sometimes this approach has made it possible for important programs to become free software." His reasoning is that selling proprietary licenses to otherwise GPL'd code is reasonable since it enables companies to do the same thing that they would be able to do if a project was dual licensed with GPL/MIT. Since he does not consider MIT/X11 style licenses wrong, merely inferior, he concludes that selling GPL exceptions is reasonable: "When I first heard of the practice of selling exceptions, I asked myself whether the practice is ethical. If someone buys an exception to embed a program in a larger proprietary program, he's doing something wrong (namely, making proprietary software). Does it follow that the developer that sold the exception is doing something wrong too? If that implication is valid, it would also apply to releasing the same program under a noncopyleft free software license, such as the X11 license. That also permits such embedding. So either we have to conclude that it's wrong to release anything under the X11 license -- a conclusion I find unacceptably extreme -- or reject this implication. Using a noncopyleft license is weak, and usually an inferior choice, but it's not wrong." http://www.fsf.org/blogs/rms/selling-exceptions |
Here's a quote by Linus Tolvards, when discussing GPLv2 versus GPLv3:
GPLv2 in no way limits your use of the software. If you're a mad scientist, you can use GPLv2'd software for your evil plans to take over the world ("Sharks with lasers on their heads!!"), and the GPLv2 just says that you have to give source code back. And that's OK by me. I like sharks with lasers.