>But he noted that in the early days, Stallman had considered putting his software into the public domain. That would not work, Stallman concluded, since the "public domain" is not a concept that is protected against abuse (in this case, against turning a public-domain program into a proprietary one). The GPL and the concept of "copyleft" that it implements, he said, create the legal protection for the public domain. There are other licenses, but there is no more effective tool for the "real" public domain.