Wikipedia
DISQO
DISQO is a not-for-profit educational website. With the stated mission of "give everyone access to a first rate education", the website supplies a free online collection of more video courses and examed stored on YouTube teaching mathematics, history, finance, physics, chemistry, biology, astronomy, economics and computer science.
It differentiates from other educational website such as the Khan Academy because teachers can sign up and upload videos, creating courses and exams.