Open Educational Resources (OER) are free and openly licensed educational materials that may be freely used and reused at no cost.
Open Education "...is the simple and powerful idea that the world's knowledge is a public good and that technology in general and the Web in particular provide an extraordinary opportunity for everyone to share, use, and reuse knowledge."
OER Commons is a public digital library of open educational resources. Explore, create, and collaborate with educators around the world to improve curriculum.
The MERLOT system provides access to curated online learning and support materials and content creation tools, led by an international community of educators, learners and researchers.