- OER Commons: Supported in part by the William and Flora Hewlett Foundation, ISKME, the Institute for the Study of Knowledge Management in Education.
- OpenStax CNX: A large collection of CC BY licensed OER supported by Rice University.
- MERLOT: Led by California State University, along with 23 other universities and institutional partners that support the operation of this repository.
- LibreTexts: A multi-institutional collaborative venture initiated at the University of California, Davis, LibreTexts’ Living Libraries incorporates OER created by students, faculty and outside experts in twelve disciplines, mainly in STEM.
- Openly Available Sources Integrated Search (OASIS): A tool developed at SUNY Geneseo’s Milne Library that searches open content from 64 different sources and contains over 160,000 records.
- The Mason OER Metafinder (MOM): The Mason OER Metafinder helps you find Open Educational Resources. It searches well-known OER repositories like OpenStax, OER Commons, MERLOT but also sites like HathiTrust, DPLA, Internet Archive and NYPL Digital Collections where valuable but often overlooked open educational materials may be found.
- Pressbooks Directory: This directory provides an index of books published across 94 Pressbooks networks. Search and filter books by keyword, subject matter, license, and more.
- Open Textbook Library: Curated catalog of open textbooks with faculty reviews housed by the University of Minnesota.
- OpenStax: Non-profit open textbook publishing company housed at Rice University that offers optional add-ons from outside partners.
- BC Campus Open Education Resources: A collection of textbooks created in British Columbia.
- Open SUNY: Textbooks developed by the SUNY system.
- CUNY Academic Works: CUNY Academic Works is a service of the CUNY Libraries dedicated to collecting and providing access to the research, scholarship, and creative and pedagogical work of the City University of New York.