Open Educational Resources (OER) are teaching and learning materials that you may freely use and reuse at no cost. They are not copyright restricted. OER have been authored or created by an individual or organization that chooses to retain few, if any, ownership rights. There are many reasons to consider adoption of OER in the classroom, including the potential freedom from commercial or other bias, and cost to students.
How do you know your options for use or reuse? OER often have a Creative Commons license or other permission to let you know how the material may be used, reused, adapted, and shared.
There are many project sites supporting not only OER for use, but tools to enable you to create or collaborate on creating your own OER.
Obviously, OER need to be rigorously evaluated as with commercial products. The tab on the left for OER research has sources on best practices and tools for adoption and evaluation of OER.
Major OER Project Hubs
Portals for finding more OER (and other open and freely usable resources)