Complete textbooks that have been reviewed by a variety of college and university faculty, and 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. Includes the OpenStax collection.
LibreTexts provides free access to more than 400 texts across a variety of disciplines, with an early emphasis on chemistry and other STEM disciplines. The libraries are supported by a nonprofit organization founded by UC-Davis Chemistry professor Delmar Larsen.
Nonprofit based at Rice University that has published more than 20 open source, peer-reviewed, textbooks in common undergraduate subjects like Algebra, History, and Psychology. Note that OpenStax textbooks can also be found through a search of the Open Textbook Library (linked above).
Online teaching, learning, and faculty development services contributed and used by an international education community. Includes open textbooks. The Material Type and Audience limiters in Advanced Search are particularly helpful.