Is it ensure, insure, or assure?
UU.S. government agency created in 1958 to facilitate research in technology with potential military applications. Most of DARPA's projects are classified secrets, but many of its military innovations have had great influence in the civilian world, particularly in the areas of electronics, telecommunications, and computer science. It is perhaps best known for ARPANET, an early network of time-sharing computers that formed the basis of the Internet.