This description of the National Diffusion Network, a nationwide system of trained educators working together to help school districts adopt tested exemplary educational programs, includes a brief history of the NDN and discussions of how programs are identified, how exemplary programs are chosen, and how school districts adopt NDN programs. The dissemination concept, why NDN has succeeded, and the importance of sharing successful educational programs are also discussed. A brief description of NDN accomplishments and a sampling of approved programs in basic skills, special, early childhood, migrant, high school, and environmental education are provided, as well as indications of future developments. (MBR)