Not only can you make the ham sandwich, but when you give ME the ham sandwich I can put mustard on it, and when I give it to some one else THEY can put cheese o

Not only can you make the ham sandwich, but when you give ME the ham sandwich I can put mustard on it, and when I give it to some one else THEY can put cheese on it. Because that's what the GPL does . It ensures that the right to modify the (sandwich)program never gets taken away from the next user in the chain.