The Net: Progress and Opportunity.

It seems that the vision of the Internet grew out of the realization that users of the first, experimental time-sharing systems formed communities. The time-sharing experiments were funded by the Advanced Research Projects Agency of the U.S. Department of Defense, originally ARPA, now DARPA, under the leadership of J.C.R. Licklider, who had championed interactive computing in an influential paper on man-machine symbiosis. Licklider soon recognized the importance of electronic communities and the initial ARPANET development was funded. The ARPANET project refined the vision and pioneered techniques used on the Internet. It was followed by the Internet, which serves the research and education communities, and by many commercial and proprietary networks. The Internet, the major research and education network, grew from the 4-node ARPANET in 1969 to an estimated 992,000 hosts by September 1992. The growth rate is over 1,000 hosts per day, and it is accelerating. Its size can only be estimated, and continues to grow while, the estimation procedure runs.