Established in 1974, the National Diffusion Network (NDN) is a diffuse association of primarily school-based instructional or other education programs that have been approved for nationwide dissemination by a federal panel, the Joint Dissemination Review Panel (JDRP). Five principles of NDN are: (1) those who develop a program are best qualified to demonstrate it to others; (2) whatever is to be demonstrated and shared must represent quality; (3) a diversity of offerings should be available; (4) informal structure, lateral communication, and a philosophy of mutual help among coequal projects are more effective than a highly structured organization; and (5) money is needed if demonstration and dissemination are to be carried out. With JDRP approval, a project automatically is part of the NDN and is described in its annual catalogue, Educational Programs That Work. Results of studies are presented to support NDN's past effectiveness. Looking toward the future, questions relating to the following topics are raised: (1) financial survival; (2) number of projects to be supported; (3) projects to be supported number of project adoptions; (4) NDN growth; and (5) ultimate effect of the new requirement that all JDRP-approved projects must resubmit every four years in order to remain in the NDN. (RL)