The GPL says that future versions of the GPL will be "similar in spirit". An "or later" GPL that allows non-free derivative works would probably not be viewed b

The GPL says that future versions of the GPL will be "similar in spirit". An "or later" GPL that allows non-free derivative works would probably not be viewed by a judge as "similar in spirit". There really is no great danger in the "or later" clause. > They can't use that to retroactively close off submitted works, but project using other licenses can't do that either. I don't understand this sentence, can you elaborate? Who can use what to retroactively lock up what, and what other licences do not allow what?