BCcampus-OpenEd - a collection of more than 150 online textbooks, the result of Canada's first government-funded open textbook project. Subjects include arts, business, health-related sciences, and trades (culinary arts).
BookBoon - free textbooks can be downloaded. Subjects include IT & programming, accounting, natural sciences, marketing & law, and engineering. Older versions of Microsoft Office are also available.
Community College Open Textbook Collaborative - a vast assortment of college textbooks easily accessible and arranged by subject, including fine arts, sciences, language, law, literature, and statistics.
Curriki - a hub for free, open course materials. Find thousands of course materials in a variety of subjects and grade levels, including free courses and textbooks.
Directory of Open Access Books (DOAB) - this website includes a large selection of international textbooks covering subjects such as business and economics, languages and literatures, mathematics and statistics, technology and engineering, and many more.
Flat World Knowledge - a college textbook publisher whose books are published under an open license. This allows professors to customize the books they order – edit, add to, mix-up – or use as-is. Students can access the books online for free or can pay for print-on-demand and audiobook versions.
InTechOpen - the world's largest science, technology, and medicine open access book publisher, with nearly 3,000 books and more than 95 million downloads.
MERLOT - Multimedia Educational Resources for Learning and Online Teaching (MERLOT) is a project of California State University and offers peer reviewed online teaching and learning materials.
OER Commons Open Textbook Hub - a platform on which educators can create or remix open educational resources for lessons and modules. An extensive library includes lesson plans, video/audio lectures, syllabi, textbooks, simulations, and full courses. A section specifically for STEM-related materials is linked to the home page for easy access.
Open Access Textbooks Websites - a FIPSE grant project, creating a model for open textbook implementation. This is their list of open textbooks sites.
Open Culture - a collection of 200 free textbooks from art history to physics and business. Various copyrights -please check for open access.
Open Oregon Educational Resources - an online collection of free textbooks intended specifically for community college students.
OpenStax - offers students free textbooks that meet scope and sequence requirements for most courses. These are peer-reviewed texts written by professional content developers.
Project Gutenberg - the place where you can download 33,000 free books! This is a great resource for Literature classes and books for young children.
Saylor Academy - a collection of more than 100 open textbooks in a variety of viewing formats, most notably in PDF.
ScienceDirect - a leading full-text scientific database offering journal articles and book chapters from more than 2,500 journals and almost 20,000 books.
Smarthistory - a free, not-for-profit, multi-media web-book designed as a dynamic enhancement (or even substitute) for the traditional art history textbook. Organized by artist, theme, or time period, it currently hosts over 300 essays and almost 600 unscripted video conversations.
SpringerOpen Books - authors in all disciplines now have the opportunity to publish open access books, including complete monographs, edited volumes, proceedings and SpringerBriefs. SpringerOpen books are published under the Creative Commons Non-Commercial (CC BY-NC) license, so they can be reused and redistributed for non-commercial purposes as long as the original author is attributed.
Suny Open Textbooks - a collection of free online textbooks developed by faculty of the State University of New York (SUNY) system. New titles are forthcoming as well.
Textbook Revolution - free educational materials available as PDF files, e-books, or web sites. "[This site] is a student-run site dedicated to increasing the use of free educational materials by teachers and professors."
Wikibooks - a Wikimedia community for creating a free library of educational books that anyone can edit. Rather than be subject to expensive static books, Wikibooks readily encourages copying, modifying, reusing, and free distribution of its books.