- Open Yale Courses
Open Yale Courses offers free online introductory courses created by different colleges at Yale.
- MIT Open Courseware
MIT Open Courseware started in 2002 and has collected over 2,000 courses in different areas, such as business, engineering, arts, and music.
- Academic Earth
Academic Earth collected video lessons from top-notch universities around the globe, including UC Berkeley, Harvard University, Princeton University, Stanford University, and so on.
- Khan Academy
Khan Academy now features thousands of video lessons, covering all areas. The content is offered in different languages for a non-discriminatory learning experience.
- Crash Course YouTube Channel
Crash Course is an educational YouTube Channel established by the Green brothers. The channel has more than ten million subscribers and has received over a billion views.