This site, created and maintained by the Johns Hopkins School for Public Health, provides access to open courseware and course materials for various health-related courses. Note that the textbooks assigned, however, are not always open textbooks.
This website, created by the Massachusetts Institute of Technology (MIT), provides access to open course materials from a wide variety of classes. These materials can include video lectures, online textbooks, exams, assignments, problem solving videos, lecture slides, and more. Note that not all textbooks assigned are open textbooks.
OER Commons, created by nonprofit Institute for the Study of Knowledge Management in Education (ISKME), is a hub providing access to material types including data, activities, interactive items, video and audio lectures, and more.
Skills Commons is a website developed in conjunction with the Department of Labor and California State University (MERLOT) to provide access to open learning materials (syllabi, quizzes, activities, and more) related to the workforce and jobs.
This website, created by students and faculty at UC Davis, is a set of interconnected pages put together to replace traditional textbooks. So far, there are individual areas of the site dedicated to chemistry, biology, geology, mathematics, statistics, physics, social sciences, engineering, medicine, agriculture, photosciences, and humanities (hover your mouse over the images near the top of the page to find the subject you want, and then click on the link to the site of your choice in the bar near the top of the page).
This website, hosted by Washington state community and technical colleges, offers a gateway to open course materials for various introductory courses. Note that the materials themselves are hosted in Google Drive; login is not required for access. Not all textbooks assigned by these courses are open.
This website, created by Carnegie Mellon University, provides instructors with access to course modules with embedded assessments for students. Note that instructors wishing to use this material through this platform and to save records of student activity will have to create a login name and password.