DO-IT (Disabilities, Opportunities, Internetworking, and Technology). Provides a large collection of resources for increasing the participation of individuals with disabilities in challenging academic programs and careers.
GeoGebra Free, open source dynamic mathematics software joining geometry, algebra, and calculus.
Discovery-Education School (Many free resources compiled by Kathleen Schrock)
Science education textbooks co-edited by ASU’s Julie Luft. You may purchase these books from the NSTA store or click on the “contents” tab and print pdf files of all chapters for free.
Luft, J., Bell, R. L., & Gess-Newsome, J. (Eds.) (2008). Science as Inquiry in the Secondary Setting . VA: National Science Teachers Association Press. A NSTA best-seller despite the availability of a free edition.
Free STEM Educational Materials