Saylor.org Academy
a non-profit organization sponsored by the Saylor Foundation, they are focused on bringing "freely available education to all." Founded in 1999 by Michael Saylor, they have created online courses curated from open content found on the Web. The courses are marketed toward students who just want to learn, and are working on some methods for offering credentials. For faculty, Saylor is a great site to start your search for OER by subject.
Saylor.org does not house content, but links to outside resources.
Lists of the Academic Consultants by subject area are available.
Lists of the Content Review Panels by subject area are also available.
They also have a collection of open textbooks.
Recommended by librarians for the Art History, Business, Engineering, History, Political Science and Psychology subject areas.