Flat World Knowledge: Our books might feel like your current book for a minute. They are written by leading experts and are peer-reviewed, edited, and highly developed. They are supported by test banks, .ppt notes, instructor manuals, print desk copies, and knowledgeable service representatives. There the similarity ends. Instead of $100 plus, our books are FREE online. Students enter the URL they're given by their instructor and start reading. It's that easy. No tricks. No popup ads. No "a premium subscription is needed for that". In fact, our free online books go beyond what standard print editions provide with integrated audio, video, and interactive features, powerful search capabilities, and more.

Community College Open Textbook Collaborative (CCOTC), funded by The William and Flora Hewlett Foundation, is a collection of colleges, governmental agencies, educational nonprofits, and other education-related organizations. The collaborative provides training for instructors adopting open resources, peer reviews of open textbooks, an online professional network, support for authors opening their resources, and other services.

Global Text Project: The project will create open content electronic textbooks that will be freely available from a website. Distribution will also be possible via paper, CD, or DVD. Our goal initially is to focus on content development and Web distribution, and we will work with relevant authorities to facilitate dissemination by other means when bandwidth is unavailable or inadequate. The goal is to make textbooks available to the many who cannot afford them.

Textbook Revolution is a student-run site dedicated to increasing the use of free educational materials by teachers and professors. We want to get these materials into classrooms. Our approach is to bring all of the free textbooks we can find together in one place, review them, and let the best rise to the top and find their way into the hands of students in classrooms around the world.

ManyBooks.net: Browse through the most popular titles, recommendations, or recent reviews from our visitors. Perhaps you'll find something interesting in the special collections. There are 26,320 eBooks available here and they're all free!

Worldwide Center of Mathematics was founded in the fall of 2008 by David B. MaSBASSEy, an award-winning professor, with 26 years of college teaching experience, and a leading research mathematician in the area of singularities. The physical offices of the Center are located in Cambridge, Massachusetts, USA. The purpose of the Center is to promote and disseminate mathematical knowledge at all levels ranging from college-preparation to research-level material.

Open Textbook Catalog: This catalog is a resource to help connect professors with some of the top open textbooks currently available. Since open textbooks are based online (print copies are optional), they can be difficult to locate or evaluate for quality. This catalog provides information to help make finding a free, open textbook less time consuming for instructors. Click here to download a PDF list of the titles in the catalog.

Open Text Book Repository is a registry of textbooks (and related materials) which are open that is free for anyone to use, reuse and redistribute. It is run by the Open Knowledge Foundation. The domain name was kindly donated to us by Steve Coast of Open Street Map.