Khan Academy offers free instructional videos and practice exercises for self-study in and outside of the classroom. Khan Academy has lessons on math, science, computer programming, history, commerce, arts, economics, and more. Their lessons help students from kindergarten to undergrad and postgrad levels.

www.khanacademy.org

MIT OpenCourseWare (MIT OCW) is an initiative of the Massachusetts Institute of Technology (MIT) to put all of the educational materials from its undergraduate – and graduate-level courses online, freely and openly available to anyone, anywhere. MIT OpenCourseWare is a large-scale, web-based publication of MIT course materials. As of December 2015, over 2,300 courses were available online and the initiative has inspired more than 250 other institutions to make their course materials available as open educational resources through the Open Education Consortium.

ocw.mit.edu

The National Programme on Technology Enhanced Learning (NPTEL), a project funded by the MHRD, provides e-learning through free online Web and Video courses in Engineering, Sciences, Technology, Management and Humanities. This is a joint initiative by seven IITs and IISc Bangalore. Other selected premier institutions also act as Associate Partner Institutions. NPTEL is a curriculum building exercise and is directed towards providing learning materials in science and engineering by adhering to the syllabi of All India Council for Technical Education and the slightly modified curricula of major affiliating Universities.

nptel.ac.in

Coursera works with universities and other organizations to offer online courses, specializations, and degrees in a variety of subjects, such as engineering, humanities, medicine, biology, social sciences, mathematics, business, computer science, digital marketing, data science, and others

www.coursera.org

Udacity is a for-profit educational organization offering free and paid massive open online courses (MOOCs). While it originally focused on offering university-style courses, it now focuses more on vocational courses for professionals.

www.udacity.com

edX is a non-profit organisation that provides massive open online course (MOOCs). It hosts online university-level courses in a wide range of disciplines to a worldwide student body, including some courses at no charge. EdX differs from other MOOC providers, such as Coursera and Udacity, in that it is a nonprofit organization and runs on the Open edX open-source software. The Massachusetts Institute of Technology and Harvard University created edX in May 2012. More than 70 schools, nonprofit organizations, and corporations offer or plan to offer courses on the edX website. As of 29 December 2016, edX has around 10 million students taking more than 1,270 courses online.

www.edx.org

The University of Minnesota has created the Open Textbook Library, which is a collection of Open textbooks that have been funded, published, and licensed to be freely used, adapted, and distributed. These books have been reviewed by faculty from a variety of colleges and universities to assess their quality. These books can be downloaded for no cost, or printed at low cost. All textbooks are either used at multiple higher education institutions; or affiliated with an institution, scholarly society, or professional organization.

open.umn.edu

OpenStax is a nonprofit initiative based at Rice University that produces openly licensed college textbook since 2012. Their library produces freely downloadable textbooks for college and AP courses used by hundreds of thousands of students.

OpenStax.org