Why should programs say “Version 2 of the GPL or any later version”?
From time to time, at intervals of years, we change the GPL—sometimes to clarify it, sometimes to permit certain kinds of use not previously permitted, and sometimes to tighten up a requirement. (The last change was in 1991.) Using this “indirect pointer” in each program makes it possible for us to change the distribution terms on the entire collection of GNU software, when we update the GPL. If each program lacked the indirect pointer, we would be forced to discuss the change at length with numerous copyright holders, which would be a virtual impossibility. In practice, the chance of having uniform distribution terms for GNU software would be nil. Suppose a program says “Version 2 of the GPL or any later version” and a new version of the GPL is released. If the new GPL version gives additional permission, that permission will be available immediately to all the users of the program. But if the new GPL version has a tighter requirement, it will not restrict use of the current version o
