College Open Textbooks - provides college level textbook listings by subject as well as provides reviews of textbooks, and background information/credentials of reviewers
Learning Pod - provides multiple choice quiz questions on a variety of subjects, arranged by educational level and provides students with the correct answer after they select their answer
Merlot II - allows users to browse materials by discipline as well as browse by material type. Also allows users to search for specific materials. Includes learning exercises. Does not always show educational level of materials.
Minnesota Libraries Publishing Project - offers patrons a free self-publishing service through Pressbooks and Biblioboard
MIT OpenCourseWare - provides an extensive variety of course materials, including lecture notes and assignments, as well as a listing of open textbooks users can browse by subject area. Some course reading materials require purchase through Amazon.
OER Commons - digital library in which users can search materials by subject area, educational level, material type, and format
OpenStax - offers open access textbooks browsable by subject, mostly on math and science subject fields
UmbraSearch - provides a large database of images and texts relating to African American studies