Where to find Open Books
OER has the most number of resources dedicated to General Ed courses, this is a list of the places where you can find complete textbooks that are free and open to use.
2012 Book Archive Creative Commons-licensed copies of all the books which were available online from a specific publisher at the end of 2012.
American Institute of Mathematics approved open textbooks.
Aviation Handbooks and Manuals Open Textbooks on Aviation from the Federal Aviation Administration (US).
BCCampus OpenEd is a collection of open textbooks aligned with the top 40 highest-enrolled subject areas, trades, technology, and skills training.
Bookboon Online textbooks for free.
FreeBooks4Doctors Free medical textbooks.
Google Books Some books presented in this mass conglomeration of scanned books are fully available, most are excerpted.
Highly Rated Textbooks by Cool4Ed.
INTECH Science, Technology & Medicine Open Access books.
Knowledge Unlatched Free access to scholarly content.
Libretexts Multi-institutional collaborative effort to improve education at all levels of higher learning by developing Open Access Resources.
Loyal Books Free Public Domain Audiobooks and eBooks Downloads.
Lumen Learning Boundless
Lyryx Open Textbooks Lyryx offers high-quality open textbooks in the fields of accounting, mathematics, and economics. They also have optional added (paid) resources such as homeworks and quizzes to accompany the open textbooks.
MUSE in collaboration with Cornell University Press.
NOBA teach and learn psychology for free.
OAPEN freely accessible academic books, mainly in the area of humanities and social sciences.
Openhumanitiespress International, scholar-led open access publishing collective.
Open SUNY Textbooks State University of New York.
Open Culture Stanford University.
Open Textbook Library University of Minnesota.
Project Gutenberg mostly public domain books.
Textbook Revolution a student-run site dedicated to increasing the use of free educational materials by teachers and professors.
The WAC Clearinghouse Writing and Composition.
The Public Domain Review focus on works which have now fallen into the public domain.
Writing Commons Writing and Research.