Z:gnu-www-ja-google-engineering-talk--9afe1f-But then we say, "you are auth/en

But then we say, "you are authorized to make copies, you are authorized to distribute them, you are authorized to modify this program and you are authorized to publish modified or extended versions." But there is a condition, and the condition says that any program you distribute that contains any substantial part of this must, as a whole, be distributed under these conditions, no more and no less. Which means that, no matter how many people modify the program or how much, as long as any substantial amount of our code is in there, that program must be free software in the same way. In effect, we guarantee that nobody can put himself between you and me and strip off the freedom and pass the code on to you missing the freedom. In other words, forbidding is forbidden.