content: So isn't it protecting someone from being forced to give up the source code of their software to some other party?      Please familiarize yourself with the GPL v2 that Linux uses:    https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html  The first part gives you a bunch of rights- if I'm the writer of the GPLed code, I agree that Microsoft (for instance) can modify my code, do whatever they want with my code- but if they distribute the binary to people, they have to include the source code for that.    This is the ONLY reason why everything released under GPL isn't immediately eaten by closed source companies-  if they modify the code (by adding their own special sauce) and then distribute the binary, they are forced to distribute all their code too.    So Microsoft could take all the Linux code, make their own mostly incompatible, fully locked down OS out of it (and they could do that today), but the key is, right now, were they do to that, you could make them release all the code for it- so they couldn't control it, someone else could  fork it for free and you would use that version.    This clause prevents the enforcement clause of the GPL from applying.    It ends all open source in most of the world, US most definitely included, by opening it all to plunder- but only by corporations.  YOU don't get that immunity, because you aren't making "mass market software".  It specifically and purposefully gives Microsoft and other large corporations unlimited rights to take ownership of all GPLed code in the world.