OpenLearn is a source of over 600 free online courses from The Open University.
CK-12 - Lots of resources for teachers including e-text books (flex-books), multimedia resources, and assessment materials. Students have access to lessons with videos, texts, study aids, and exercises.
Curriki - Resources can be brosed by subject and by grade level. Includes ratings by staff and members. Amount of content for each lesson varies.
Gateway to 21st Century Skills - Educational resources for teachers. Items are tagged so the user knows whether they are free, available as a pdf, interactive, and so on. Clicking on a tag allows users to browse by that tag (such as free).
Gooru - Resources for Middle and High School, multimedia lessons browseable by subject. Some lessons include quizzes.
HippoCampus - A collection of resources for high school.
OER Commons - Allows sharing, registered users can save favorite resources. Status indicators show whether a resource has been evaluated, rated, and sharing rules.
National Repository of Online Courses - Repository with several high school and college courses.
Power My Learning - Interactive learning games, instructional videos, suggestions for teachers to incorporate activities into lesson plans, and more. Content can be added to playlists and filters can be used to locate stuff by sugect or grade level.
PBS Learning Media - Searchable digital resources including videos, games, audio clips, photos, and lesson plans. PBS LearningMedia is free for educators and registered users can save and share content. Teachers can sign their classes up, controlling things such as naming conventions.
The Community College Consortium for Open Educational Resources - CCCOER is a joint effort by the OER Center for California, Foothill-De Anza Community College District, the League for Innovation in the Community College and many other community colleges and university partners to develop and use open educational resources (OER) and especially open textbooks in community college courses.
OpenStax is a non-profit digital ecosystem serving millions of users per month in the delivery of free educational content to improve learning outcomes.
Free Online Course Materials is a California State University MERLOT collection of over 35,000 open course materials.
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 Open Course Library from Washington State University, is a collection of expertly developed educational materials – including textbooks, syllabi, course activities, readings, and assessments – for 81 high-enrollment college courses. 42 courses have been completed so far, providing faculty with a high-quality, affordable option that will cost students no more than $30 for textbooks.
OER Commons was created as a network for teaching and learning materials, the web site offers engagement with resources in the form of social bookmarking, tagging, rating, and reviewing.
The Open Education Resource (OER) Foundation is an independent, not-for-profit organization that provides leadership, networking and support for educators and educational institutions to achieve their objectives through Open Education.
WikiEducator is a community project working collaboratively with the Free Culture Movement towards a free version of the education curriculum by 2015. Driven by the learning for development agenda WikiEducator is developing free content for use in schools, polytechnics, universities, vocational education institutions and informal education settings.
The World Digital Library (WDL) makes available on the Internet, free of charge and in multilingual format, significant primary materials from countries and cultures around the world.