Open educational resources (OER) are learning materials such as textbooks, online homework, test banks, interactive modules and even entire courses that are freely available to be used, remixed, improved, and redistributed. They are often available under a Creative Commons license. The William and Flora Hewlett Foundation, which has been supporting OER since 2002, defines them as "high-quality teaching, learning, and research materials that are free for people everywhere to use and repurpose."
