OER Commons (Open Educational Resources)Open Educational Resources (OER) is a "digital library and network" that consists of "teaching and learning materials that you may freely use and reuse at no cost. Unlike fixed, copyrighted resources, OER have been authored or created by an individual or organization that chooses to retain few, if any, ownership rights."
Following are "some examples of OER material: full university courses; interactive mini-lessons and simulations; adaptations of existing open work; electronic textbooks; and elementary school and high school (k-12) lesson plans, worksheets, and activities."