Coursera https://www.coursera.org Coursera was founded by Stanford computer science professors Andrew Ng and Daphne Koller. Originally launched with partners Stanford, Michigan, Penn, and Princeton, many other universities have since joined. (see Wikipedia) It is a for-profit educational company.
edX Harvard, MIT, and UC Berkeley offer courses in edX https://www.edx.org/
MITx courses offer "certificates" that will bear the name of the not-for-profit overseeing the edX program, not MITs.
The Internet Archive provides an archive for free/open courses. http://www.archive.org/details/education
iTunes University from Apple.
Lumen Learning https://courses.lumenlearning.com/catalog/lumen
Founded by David Wiley and Kim Thanos,
MIT's OpenCourseWare project has been one of the biggest inspirations for the OER movement, but many of their course pages are just outlines. More interesting are their courses with "substantial" audio-visual content. http://ocw.mit.edu/courses/audio-video-courses/
My Education Path says it list more than 15,000 courses
National Repository of Online Courses (NROC) from the Monterey Institute
NROC content is distributed free-of-charge to students and teachers at public websites including HippoCampus.
Open Courseware Consortium is a rich source of courses. OCW now calls itself the Open Education Consortium.
Open Course Library from the Washington State Board for Community and Technical Colleges (SBCTC): http://opencourselibrary.org/
Oxford http://podcasts.ox.ac.uk/open/all offers free but limited video course broadcasts.
Saylor Foundation https://learn.saylor.org/course/index.php?categoryid=2
According to Inside Higher Ed, the Saylor foundation has been working with Excelsior and Straighterline to provide an indirect way for students to get college credit for their courses. Interestingly, Excelsior College has partnered with Pearson in their UExcel credit by exam system, which they claim to be the "...only lower-level CBE program developed and administered by a regionally-accredited institution of higher learning..."
Stanford also is offering free courses http://online.stanford.edu/courses
Udacity http:www.udacity.com Udacity is the outgrowth of free computer science courses at Stanford and was founded by Sebastian Thrun, David Stavens, and Mike Sokolsky. (see Wikipedia) Udacity is another for-profit organization.
Scroll down the page and look for the link "View all Subjects" to see what courses are listed by subject
Affordable Learning Solutions (from the CSU)
Applie Math and Science Educational Repository
Khan Academy Has over 2100 videos, mostly about math and science topics
MERLOT online course portal includes links to course materials and whole courses
The Open Culture website says it has links to 1000 free courses http://www.openculture.com/freeonlinecourses
Dan Colman at Stanford University is the the "lead editor" of the site.
Meriam Library | CSU, Chico