The Open Textbook Library, hosted by the University of Minnesota - Twin Cities, indexes original open textbooks currently in use at colleges and universities. Faculty from Open Textbook Network (OTN) member institutions can post public reviews of textbooks in the Open Textbook Library. The University of Missouri, through MOBIUS, is an OTN member.
OpenStax, a nonprofit educational initiative based at Rice University, publishes high-quality, peer-reviewed, openly licensed college textbooks that are absolutely free online and low cost in print. More than 3 million college and high school students currently use OpenStax textbooks.
While the Community College Open Textbook Collaborative focuses on providing textbooks for two-year colleges, many of the resources linked here are peer-reviewed and suitable for lower-division undergraduate coursework.
The DPLA is an all-digital library that aggregates metadata for millions of photographs, manuscripts, books, sounds, moving images, and more from libraries, archives, and museums around the United States. Material which is out of copyright or openly-licensed is available in full.
A free publication service by the Association of American Medical Colleges (AAMC) and the American Dental Education Association (ADEA) of peer-reviewed medical education materials licensed under Creative Commons open licenses.