Generally accepted as the first (1971) sophisticated packet network architecture,ARPANET was designed to link computers on a time-share basis in order to share computer resources more cost-effectively in support of various defense, higher education, and research and development organizations. In 1983, the majority of ARPANET users spun off to form the Defense Data Network (DDN), also called MILNET (Military Network), which included European and Pacific Rim continents. Locations in the United States and Europe that remained with ARPANET then merged with the Defense Advanced Research Project Agency Network to become DARPA Internet.