by F.

Connexions is a project at Rice University that aims to create high quality, low cost textbooks and other educational materials:

Connexions is an environment for collaboratively developing, freely sharing, and rapidly publishing scholarly content on the Web. Our Content Commons contains educational materials for everyone — from children to college students to professionals — organized in small modules that are easily connected into larger courses. All content is free to use and reuse under the Creative Commons “attribution” license.

It’s very, very cool. See more here. There’s a talk about the project here.