College Open Textbooks (COT) focuses on textbooks for lower division classes. COT is not a repository of open textbooks; our listings point to textbooks on many repositories.

MIT OpenCourseWare (OCW) is a web-based publication of virtually all MIT course content. OCW is open and available to the world and is a permanent MIT activity.

The B.C. Open Textbook Project is funded by the BC Ministry of Advanced Education, and BCcampus is tasked with managing it. A goal of the Project is to provide flexible and affordable access to higher education resources in B.C. by making available openly-licensed textbooks in the highest-enrolled academic subject areas. A

The WDL makes it possible to discover, study, and enjoy cultural treasures and significant historical documents on one site, in a variety of ways. Content on the WDL includes books, manuscripts, maps, newspapers, journals, prints and photographs, sound recordings, and films.

Europeana.eu is the EU digital platform for cultural heritage. More than 3,000 institutions across Europe have contributed to Europeana. These range from major international names like the Rijksmuseum in Amsterdam, the British Library and the Louvre to regional archives and local museums from every member of the European Union. Together, their assembled collections let users explore Europe's cultural and scientific heritage from prehistory to the modern day.

Open source textbooks that are written by professional content developers who are experts in their fields and undergo a rigorous peer review process. All textbooks meet standard scope and sequence requirements.

The Open Textbook Library provides a growing catalog of free, peer-reviewed, and openly-licensed textbooks. The Open Textbook Library is supported by the Center for Open Education and the Open Textbook Network.

MERLOT is a curated collection of free and open online teaching, learning, and faculty development services contributed and used by an international education community. The MERLOT Collection is made up of over 40,000 materials in 19 different material type categories.

OER Commons helps educators, students, and lifelong learners avoid time-consuming searches and find exactly the right materials. With a single point of access from which they can search, browse, and evaluate resources in OER Commons’ growing collection of over 50,000 high-quality OER everyone can more efficiently find what they need.