The Internet began in the late 1960s with the development of ARPANET. ARPANET provided a limited number of researchers with shared, interactive communications between computing systems at different locations and developed key innovative technologies on which the Internet still depends. Some of these include:

• "Packet switching" in which a message is divided into packets that are transmitted to their destination and reassembled -- rather than using a dedicated circuit as in the telephone system or "store and forward" that is used in the telegraph system

• A distributed rather than a centralized network -- even when some nodes fail, the remaining network continues to function, although perhaps at reduced capability

• Adaptivity -- packets can be transmitted to the same destination over different parts of the network based on current network load and connectivity

• The Transmission Control Protocol (TCP) and the Internet Protocol (IP) were developed in the 1970s and early 1980s under ARPA sponsorship to enable different networks to interoperate. TCP/IP made it possible for ARPANET, the ARPA packet radio network, and the packet satellite network, each with different packet sizes and network transmission speeds, to interoperate.

While initially an experimental system, the need for a stable network emerged as the user community grew. MILNET was split from the ARPANET for use by Department of Defense users. Federal agencies established networks to support their R&D communities: NSF created NSFNET for the university research community, NASA built the NASA Science Internet (NSI), and DOE created the Energy Sciences Network (ESnet). These networks and an ever growing profusion of local area networks and regional networks form the HPCC component of the Internet, a "network of networks," and demonstrate the fundamental strength of new networking technologies created in the early ARPANET.

The recent phenomenal growth of the Internet beyond the HPCC community is the result of educational, public service, private sector, and personal investment. Today there are more than 27,000 networks in the U.S., an increase of 350 percent over that reported on these pages a year ago. Non-U.S. networks number more than 21,000, an increase of 225 percent. More than 1,500 U.S. colleges and universities, 1,500 high schools and 1,700 elementary schools in the U.S. have full Internet connectivity.

The HPCC Program has directly stimulated the emergence of a vigorous and highly competitive private sector industry in Internet hardware, software, and connectivity in which the U.S. is a world leader.