The American Institute of Mathematics (AIM) seeks to encourage the adoption of open source and open access mathematics textbooks. The AIM Editorial Board has developed evaluation criteria to identify the books that are suitable for use in traditional university courses.
Operated by Cornell University, arXIv.org provides open access to over one million e-prints in Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance, Statistics, Electrical Engineering and Systems Science, and Economics.
An initiative from the B.C. Campus for open access textbooks for the university campus.
E-book publisher providing online textbooks for free download.
College Open Textbooks
Collaboration of multiple organizations and colleges promoting awareness and adoption of open access textbooks. Includes a list of open access and low cost textbooks for university classes.
The directory is open to all publishers who publish academic, peer reviewed books in Open Access and should contain as many books as possible, provided that these publications are in Open Access and meet academic standards.
Open access publisher of science, technology & medicine.
The Multimedia Educational Resource for Online Teaching (MERLOT), developed by the California State University Center for Distributed Learning offers access to thousands of open educational materials.
Some of these online textbooks are open-licensed electronic versions of print books. Others are self-published online books, or course notes which are so thorough that they serve as an alternative to a conventional textbook.
The OAPEN Library contains freely accessible academic books, mainly in the area of humanities and social sciences. OAPEN works with publishers to build a quality controlled collection of open access books, and provides services for publishers, libraries and research funders in the areas of deposit, quality assurance, dissemination, and digital preservation.
Community College Consortium for Open Educational Resources
Open Access Textbooks
FIPSE Grant Project with links to other initiatives and a number of other resources.
OpenBook Publishers is run by scholars who are committed to making high-quality research available to readers around the world. It publishes monographs and textbooks in all areas, and offer the academic excellence of a traditional press, with the speed, convenience and accessibility of digital publishing. All books are available to read for free online.
Rice University's open access initiative, with books organized by subject. OpenStax College is a nonprofit organization committed to improving student access to quality learning materials. OpenStax's open textbooks are developed and peer-reviewed by educators to ensure they are readable, accurate, and meet standard scope and sequence requirements.
OER Commons offers a comprehensive infrastructure for curriculum experts and instructors at all levels to identify high-quality OER and collaborate around their adaptation, evaluation, and use to address the needs of teachers and learners.
The Open Textbook Library provides a growing catalog of free, peer-reviewed, and openly-licensed textbooks housed at the University of Minnesota and sponsored by the Open Textbook Network.
List of open access books maintain by Saylor Academy, an online open course institution.
Student-run site with links to free textbooks and educational resources.
The open-content textbooks collection that anyone can edit.