The project is a collection of free textbooks with supporting book-based texts, that is being written collaboratively on this website. The site is a WikiWiki, 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 opened in response to a request by Wikipedia's Karl Wick for a place to start building open content textbooks such as organic chemistry and physics in order to bring education to humanity and reduce the costs and other limitations to top-quality learning materials. It was started on July 10, 2003 and there are 447 modules that are being worked. By July 31st 2003 there were 123 modules and 47 registered users.
Some of the first books were completely original and others began as text copied over from other sources of GNU FDL textbooks found on the Internet. All of the site's content is covered by the GNU Free Documentation License. Contributions remain the property of their creators, while the copyleft licensing ensures that the content will always remain freely distributable and reproducible. See copyrights for more information.
Controversies have included the scope of the project (just textbooks or all kinds of books) as well as how best to deal with licensing of the site content, as well as the name and future URL for the project.