Free Software / The GNU General Public License

The GPL, or GNU General Public License, is the manifestation of a dream, the dream that all information can be freely accessed by anyone. Many pains could be eased and many wars could have been prevented, if there had only been more information (to both sides).

This is actually the Hacker Ethics. The GPL is much more specific, but aims at the same target. It enables the author of software to make it free (free not as in "free of charge", but as in "freedom"). To give to the users the freedom to read the source of the software, to copy the software and even to modify the source and redistribute the changes. And the clue behind the GPL is that you cannot "un-free" the software, once it is released under the GPL, because every change of the source and every software that uses the GPL'ed software must also be released under the GPL.

The most prominent example of free software is the Linux kernel. It is developed by a collaborative community all around the world, which was made possible by the Free Software Movement and the GPL.

The man behind the GPL and the founder of the Free Software Foundation is Richard Stallman. If you want to know more about this topic, please read on there.