There are hundreds of open source licenses, based on the idea of free (as in liberty) software. I gave a presentation for the UTU course Intellectual Property Rights and Research examining open source licenses.
Too long; didn’t read
Short summary on choosing an open-source license:
- Want it open, easy and don’t care about much else? You probably want MIT
- Want it open, but forbid adaptations or commercial use? You probably want one of the Creative Commons licenses
- Want it open, and want to keep derivates open and free, securing Freedom 0 for users in the future (and hold less rights for yourself, e.g. patents)? You probably want GNU GPLv3
More options categorized on Github’s Choose a license.