* Wiki books
- dedicated to building a complete education curriculum by 2015
- free, flexible textbooks for the whole American educational syllabus
* Khan Academy
- a series of tutorial videos, mostly of science and maths, explaining concepts very well.
* MIT's YouTube channel
- Includes entire lecture series. The one on linear algebra in damn good.
* Open Yale Courses
* Stanford's YouTube channel
* United Nations University OpenCourseWare
* John Hopkins OpenCourseWare
- free and open-source software that teaches ideas in innovative ways. For kids
* Open University's Open Learn
* P2P university
- Open educational content in hundreds of subjects.
* List of educational video websites on Wikipedia
* Open Culture
- list online courses
* Wolfram Demonstrations Project
- A compilation of pretty interactive visualizations of hundreds of phenomena in science, mathematics, music and other areas.