BookBoon
BookBoon offers over 1,500 ebooks in seven languages, directly available for download from the website. This company's collection is strongest in the fields of business, engineering and math.
College Open Textbooks by Subject
College Open Textbooks is a collection of sixteen educational non-profit and for-profit organizations, affiliated with more than 200 colleges, that is focused on driving awareness and adoptions of open textbooks.
Connexions
Connexions is a place to view and share educational material made of small knowledge chunks called modules that can be organized as courses, books, reports, etc. Anyone may view or contribute.
Creative Commons: Science
Creative Commons: Science provides listings of sites that offer scientific and technical research articles available under a Creative Commons license, which allows users to share them freely.
Digital Public Library of America
The Digital Public Library of America is a portal providing innovative ways to search and scan through the united collection of millions of items digitized by libraries, archives, and museums in the United States.
Directory of Open Access Books
Directory of Open Access Books (DOAB) offers a collection of over 700 open access, peer-reviewed books in a variety of disciplines.
Flat World Knowledge
Flat World Knowledge offers low-cost online textbooks in many different disciplines and also offers print versions.
Flat World Knowledge Book Archive
Before Flat World Knowledge started charging for its online textbooks in January 2013, they were available free under a Creative Commons license. These freeversions of the textbooks are still available in the Flat World Knowledge Book Archive.
Free Textbook Lookup Tool
CSU's Affordable Learning Solutions' Free Textbook Lookup Tool lets you enter the ISBN of a textbook to find related FREE open textbooks.
Getty Research Portal
"The Getty Research Portal™ is an online search platform providing global access to digitized art history texts in the public domain." It allows you to find and download complete digital copies of publications for the study of art, architecture, material culture, and related fields.
Google Play
Google Play provides free access to ebooks, newspapers, and magazines in a wide array of subjects. Titles are usually historic, but there is also some contemporary titles. Free and paid books will appear in your search.
HathiTrust Digital Library
HathiTrust provides free access to ebooks in a wide array of subjects. Titles are usually historic, but there is also some contemporary information.
Inkling
Inkling offers interactive textbooks for the iPad. Single chapters are available for free, but full textbooks cost about as much as their print versions.
Internet Archive
Internet Archive provides a gateway to a variety of free ebook collections. It includes a range of fiction, popular books, children's books, historical texts and academic books.
MERLOT
MERLOT is a program of the California State University, in partnership with higher education institutions, professional societies, and industry. Here you'll find ebooks as well as courseware and other learning material.
The National Academies Press
All of the books on the National Academies Press site are available as freely downloadable PDFs. The Press is strongest in the fields of science and education.
Open Academics
Created by the University of Minnesota, Open Academics is a catalog of open textbooks reviewed by faculty members. It includes books on accounting and finance, business and management, computer science, economics, general education, humanities, law, math and statistics, natural and physical sciences, and social sciences. The over 140 books are openly licensed, complete, and suitable for adoption. All textbooks include a print option, generally for $40 or less.
Open Course Library
The Open Course Library is a collection of shareable, course materials, including syllabi, course activities, readings, and assessments designed by teams of Washington State University faculty, instructional designers, librarians, and other experts. To view, login with guest_ocl (password: ocl).
Open Courseware Consortium
Open Courseware Consortium is a collaboration of higher education institutions and associated organizations from around the world. It provides a collection of open educational content using a shared model.
Open Educational Resources Commons
The OER Commons has forged alliances with over 500 major content partners in order to provide a single point of access to the highest quality content in all disciplines from around the world.
Open Library
The Open Library provides access to over one million fiction and non-fiction titles, all online and available for free.
OpenStax College
OpenStax College is funded by several non-profit organizations including the Hewlett and Gates Foundation and provides free, digital textbooks for Physics and Sociology.
The Orange Grove
The Orange Grove is an online library of openly available instructional resources created for Florida's colleges and universities.
PLoS
The Public Library of Science, PLoS, provides open-access articles and journals in the areas of science and medicine.
Project Gutenberg
One of the original open source sites, Project Gutenberg provides access to over 39,000 ebooks, which are free because their copyright has expired. It also offers some copyrighted titles, for which the copyright holder has given permission for unlimited non-commercial worldwide use.
Saylor
Saylor provides free online courses, but unlike MOOCs, these are asynchronous and it features dozens of e-textbooks created to work with its classes.
Textbook Revolution
Textbook Revolution is a student-run site dedicated to increasing the use of free educational materials by teachers and professors.
Wikibooks
Wikibooks is part of the Wikimedia Foundation. Anyone can edit the content of a Wikibook, and books undergo no formal peer-review process. The books are browser based, and there are no printing and download options.