Academic Earth was founded by 3 benevolent in 2008. In 2012 the site was purchased by CMN (Consumer Media Network) though courses are still free. Academic Earth is all based on "self-learning" principle.
Academic Earth is not offering any kind of certificate to self learners and there is no help from academic staff. Though they are offering broad selection of video courses from different department and professions. If you know your deficiencies and what you need to learn, Academic Earth can be a great source for you.
Pictures from the Campus of Harvard University