Wikibooks

Wikibooks is a collection of open content textbooks, manuals, and other texts, with supporting book-based texts that are being collaboratively written. This site is a wiki, meaning that anyone, including you, can edit any book module right now by clicking on the edit this page link that appears in every Wikibooks module. The project was started on July 10, 2003, and there are 11,645 modules currently being worked on.

All of the site's content is covered by the GNU Free Documentation License. Contributions remain the intellectual property of their creators, while the copyleft licensing ensures that the content will always remain freely distributable and reproducible. See Wikibooks:Copyrights for more information.

Note: In order to properly instruct students in various disciplines (especially the medical sciences), some Wikibooks have content that may be considered offensive, vulgar or profane by some readers. See the content disclaimer for more information.

http://en.wikibooks.org/wiki/Main_Page