Collaborative Online Textbook Project
rocketjam writes "OpenTextBook.org is a new project to create a free, open text book 'collaboratively written by anyone on the internet', using a Creative Commons license. Citing the free software development model and the philosophy that underlies much of that effort, OpenTextBook.org's introduction says this philosophy should apply 'at its most basic to the learning of science.' They hope the project will help to counter the current governmental trend of strengthening the scope, duration and rights of intellectual property owners while cutting back on the fair use rights of individuals. The current state of the project is available as a daily snapshot pdf file which contains the introduction to the project and 9 chapters mostly covering math at this time."
Wikimedia Foundation, the one that also hosts Wikipedia, has a similar project called Wikibooks. It also runs on the same MediaWiki software as Wikipedia, and the contents are licensed under the GFDL.
The given Creative Commons license prohibits commercial usage of the material. The GNU FDL permits it - for example, the German Wikipedia is now selling printed copies of its first WikiReader book. This makes it impossible to import OpenTextBook content into Wikipedia.
The other way round, the GNU FDL requires that all derivative works permit commercial usage as well, which makes it impossible to put WikiBooks content into OpenTextBook (copyleft). Fair use would be an exception.
I love C++
If you find this interesting, check out my Free Curriculum Project and the Free High School Science Texts project (to which I am a very minor contributor).
Both of these projects use the FDL.
-Peter