Open textbooks can be defined as "textbooks that have been funded, published, and licensed to be freely used, adapted, and distributed." Typically open textbooks are available as a pdf, epub, or set of html pages that are available at no cost to students and instructors.
True open textbooks are licensed so that they can be freely printed, distributed, and even adapted with correct attribution. Vendors like Amazon and Lulu may be able to provide print copies of open texts, and they can be printed locally as well.
Open Textbook Library (OTL) is an initiative by the University of Minnesota intended to help faculty members quickly find and assess open textbooks in use at other institutions of higher education The library has collected dozens of open textbooks that are currently in use at higher educational institutions or affiliated with a higher education institution, scholarly society, or professional organization. OTL also invites faculty reviews of the textbooks in the library.
If you're looking for OER that are packaged for use, OpenStax by Rice University is a good place to start. OpenStax specializes in creating materials for general education courses like Biology 101, Introduction to Sociology, and Calculus I-III. All textbooks have been peer-reviewed and vetted by the higher education community.
These books are openly licensed, meaning that you as an instructor can modify a book for your own course, if you so choose. Modifications, like added text, links, and videos, will show in a version that you create specifically for your class. OpenStax updates their textbooks over time and pairs each book with lists of added resources like slides and exercises that you can use in class. Some of these added resources are free while others are available for a fee.
The BCcampus Open Textbook Project is an initiative in British Columbia that intends to provide open textbooks for the largest courses in the province. The BCcampus library includes textbooks developed by Canadian authors as well as other texts that have been borrowed for use by instructors in British Columbia. The library is strong in general education courses but also includes options for a number of skills and trades. Faculty reviews and ancillary resources are available for some textbooks - look for links that help you locate these in the library.
MERLOT is a program of the California State University system that invites educators to share and review OER on the MERLOT website. Items submitted to MERLOT are vetted by teams of peer reviewers with subject-area expertise. Materials on the site range widely from simulations, class activities, and media to case studies, open journal articles, and open textbooks.
Teaching Commons pulls together OER published at a number of colleges and universities including Portland State University, University of Massachusetts, University of Pennsylvania, University of South Florida, the City University of New York, and Utah State University. To find open textbooks, select "textbooks" under "types of works."
The Center for Computer-Assisted Legal Instruction (CALI) is a non-profit consortium of law schools, law libraries and related organizations with a mission to "conduct applied research and development in the area of computer-mediated legal education and creates tools that increase access to justice." Its publishing arm, eLangdell Press, publishes open and free casebooks on a range of legal topics relevant to first-year students.
UC Press E-Books Collection, 1982-2004, includes almost 2,000 books from academic presses on a range of topics, including art, science, history, music, religion, and fiction.
Pitt Press has selected these digital editions for open access, including titles from the Pitt Latin American Series, Pitt Series in Russian and East European Studies, and Composition, Literacy and Culture. The majority of these titles are out-of-print, but are now available online.
Open Book Publishers (OBP) is an independent open access academic monograph publisher based in the UK. OBP publishes monographs in PDF, XML, and HTML formats. It accepts submissions in all disciplines but specializes in social sciences and humanities. OBP is supported by library partners and does not charge authors who are accepted for publication.
OASIS is a tool that searches some 155,000 records for open material. It is being developed at SUNY Geneseo's Milne Library.