OER: Open Educational Resources

In 2008, Richard Ludlow, Chris Bruner, and Liam Pisano, founded Academic Earth with the mission of giving everyone on earth access to a world-class education. In 2012, Academic Earth was acquired by CMN.com, a leader in consumer driven-content strategy with a strong online presence in higher education.
In addition to their comprehensive collection of free online college courses, Academic Earth features an ongoing series of original videos.

Coursera was founded in 2012 by two Stanford Computer Science professors who wanted to share their knowledge and skills with the world. Every course on Coursera is taught by top instructors from the world’s best universities and educational institutions.
Learners have the option to take most courses for free or pay a fee to obtain a certificate of completion.

Founded by Harvard University and MIT in 2012, edX is an online learning destination and MOOC provider, offering high-quality courses from the world’s best universities and institutions to learners everywhere.
Open edX is the open-source platform that powers edX courses and is freely available. With Open edX , educators and technologists can build learning tools and contribute new features to the platform, creating innovative solutions to benefit students everywhere.

Saylor Academy is a nonprofit initiative working since 2008 to offer free and open online courses to all who want to learn. They offer nearly 100 full-length courses at the college and professional levels, each of which is available right now — at your pace, on your schedule, and free of cost.

Udacity began as an experiment in online learning, when Stanford instructors Sebastian Thrun and Peter Norvig elected to offer their "Introduction to Artificial Intelligence" course online to anyone, for free. Over 160,000 students in more than 190 countries enrolled.
Udacity is where lifelong learners come to learn the skills they need, to land the jobs they want, to build the lives they deserve. Udacity proudly offers aspiring learners across the globe the opportunity to participate in—and contribute to—some of the most exciting and innovative fields in the world.