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. The Editorial Board maintains a list of Approved Textbooks which have been judged to meet these criteria.

"The textbooks are created (or, where possible, re-created from existing open educational resources) by BC post-secondary faculty, reviewed by B.C. faculty and made available under a Creative Commons license."

"As a global eBook publisher, bookboon.com offers a huge range of over 1000 eBooks in seven languages, directly available to download from the website."

"Boundless helps students learn better by connecting them with the wealth of high quality, openly licensed, free educational content, as well as the tools they need to succeed."

A European open educational resources site focusing on the arts and digital humanities.

"The primary aim of DOAB is to increase discoverability of Open Access books."

"Written by the industry's top authors, our textbooks are helping improve teaching and learning at more than 2,500 leading colleges and universities worldwide."

" . . . by working together libraries can create a sustainable route to Open Access for scholarly books and secure long-term cost savings for their own institutions by sharing the costs of making HSS monographs available on a Creative Commons licence. Supporting Open Access through Knowledge Unlatched will not cost more than simply purchasing a more traditionally published title."

"We offer more than 4,000 titles in PDF format. All of these PDFs can be downloaded for free by the chapter or the entire book."

"OpenStax College is a nonprofit organization committed to improving student access to quality learning materials. Our free textbooks are developed and peer-reviewed by educators to ensure they are readable, accurate, and meet the scope and sequence requirements of your course."

"Open SUNY Textbooks is an open access textbook publishing initiative established by State University of New York libraries and supported by SUNY Innovative Instruction Technology Grants. This pilot initiative publishes high-quality, cost-effective course resources by engaging faculty as authors and peer-reviewers, and libraries as publishing service and infrastructure."

"Open textbooks are textbooks that have been funded, published, and licensed to be freely used, adapted, and distributed. These books have been reviewed by faculty from a variety of colleges and universities to assess their quality."

This document collects OER texts listed by discipline. While it is not a comprehensive list, it may be a helpful starting point.