http://www.onlinecourses.com/

"is a free and comprehensive resource that is a collection of open college courses that spans videos, audio lectures, and notes given by professors at Harvard, Princeton and MIT. We offer highly relevant courses such as iPhone Application Development from Stanford and Cyber Humor from Oxford."
(Optimized for mobile devices.)

http://en.wikiversity.org/wiki/Wikiversity:Main_Page

"Wikiversity is a Wikimedia Foundation project devoted to learning resources, learning projects, and research for use in all levels, types, and styles of education from pre-school to university, including professional training and informal learning. We invite teachers, students, and researchers to join us in creating open educational resources and collaborative learning communities."

https://www.khanacademy.org/

"Khan Academy is an organization on a mission. We're a not-for-profit with the goal of changing education for the better by providing a free world-class education for anyone anywhere. All of the site's resources are available to anyone. It doesn't matter if you are a student, teacher, home-schooler, principal, adult returning to the classroom after 20 years, or a friendly alien just trying to get a leg up in earthly biology. Khan Academy's materials and resources are available to you completely free of charge."

https://www.coursera.org/

"We are a social entrepreneurship company that partners with the top universities in the world to offer courses online for anyone to take, for free. We envision a future where the top universities are educating not only thousands of students, but millions. Our technology enables the best professors to teach tens or hundreds of thousands of students.
Through this, we hope to give everyone access to the world-class education that has so far been available only to a select few. We want to empower people with education that will improve their lives, the lives of their families, and the communities they live in."

https://www.edx.org/

"EdX is a not-for-profit enterprise of its founding partners Harvard University and the Massachusetts Institute of Technology that features learning designed specifically for interactive study via the web. Based on a long history of collaboration and their shared educational missions, the founders are creating a new online-learning experience with online courses that reflect their disciplinary breadth. Along with offering online courses, the institutions will use edX to research how students learn and how technology can transform learning–both on-campus and worldwide. Anant Agarwal, former Director of MIT's Computer Science and Artificial Intelligence Laboratory, serves as the first president of edX. EdX's goals combine the desire to reach out to students of all ages, means, and nations, and to deliver these teachings from a faculty who reflect the diversity of its audience. EdX is based in Cambridge, Massachusetts and is governed by MIT and Harvard."

http://www.core.org.cn/en/

"The China Open Resources for Education (CORE) is a non-profit organization. Its mission is to promote closer interaction and open sharing of educational resources between Chinese and international universities, which CORE envisions as the future of world education. CORE aims to provide Chinese universities with free and easy access to global open educational resources."

http://alison.com/

"ALISON* is the world's leading free online learning resource for basic and essential workplace skills. ALISON provides high-quality, engaging, interactive multimedia courseware for certification and standards-based learning.
The mission of ALISON is to enable anyone, anywhere, to educate themselves for free via interactive, self-paced multimedia. It is our belief that through ALISON, the cost of access to high-quality education can be removed.
Through the ALISON learning platform we can assist people around the world in educating themselves, thereby creating a more equitable and sustainable global society. We believe that all certifiable or standards-based learning for every subject can be made available for free online. We also believe that Article 26 of the United Nations Universal Declaration of Human Rights which states "Everyone has the right to education. Education shall be free..." will, through ALISON, become a reality. "

https://p2pu.org/en/

"Peer 2 Peer University (we mostly just say P2PU) is a grassroots open education project that organizes learning outside of institutional walls and gives learners recognition for their achievements. P2PU creates a model for lifelong learning alongside traditional formal higher education. Leveraging the internet and educational materials openly available online, P2PU enables high-quality low-cost education opportunities.
Learning for the people, by the people. About almost anything."

https://www.udacity.com/us

"Our mission is to bring accessible, affordable, engaging, and highly effective higher education to the world. We believe that higher education is a basic human right, and we seek to empower our students to advance their education and careers."

http://www.ck12.org/student/

CK12 Foundation is a non-profit that creates and aggregate high quality , curated STEM content. (STEM education is an approach to teaching and learning that integrates the content and skills of science, technology, engineering, and mathematics.)

http://studentscircle.net/live/

"Students Circle Network is now part of the Beni American University – Research and Development Projects.
Students Circle Network, a Kyrenia-area start-up founded in 2010 - is an educational social network for college and high school students by providing free course resources | materials, live teacher help to students, scholarship offers, study groups and many more students services for free.
We are currently indexing over 10,431 courses from over 200 OpenCourseWare member universities from across the globe and providing over 15 study and focus groups in Business, Computing, Engineering, Sciences and Humanities."