ARPAnet

Considered the predecessor of the Internet, ARPAnet was established by the Advanced Research Projects Agency (ARPA) in 1969 for two main reasons: to allow for the transfer of data between various institutes of research, and to answer the call of the U.S. Department of Defense for a technology that would provide messaging capabilities to the government in the event of nuclear war. Seven years earlier, ARPA hired Dr. J.C.R. Licklider to oversee how best to use emerging computer technology. Licklider is credited as being one of the first individuals to begin looking beyond the mathematical uses of computer technology and see its potential for facilitating communication between institutions and between individuals.

ARPA began formally moving forward on its plan to create a Wide Area Network (WAN) in 1967. After deciding to use Interface Message Processors (IMPs) to connect host computers via telephone lines, ARPA began looking for a contractor able to create the underlying network needed to connect the IMPs. Bolt Beranek and Newman, the Cambridge, Massachusetts-based research and development outfit that Licklider left when he began working for ARPA, successfully bid on the project. The final piece of technology needed—the protocol, or set of standards that would actually allow the host sites to communicate with one another—was developed internally by the Network Working Group.

The first three organizations connected by ARPAnet were the University of California at Los Angeles (UCLA), the Stanford Research Institute, and the University of Utah. Via ARPAnet's Network Control Protocol (NCP), users were able to access and use both computers and printers in other locations and transport files back and forth between computers. Ironically, one of the most important developments in ARPAnet technology, a more sophisticated network code known as Transmission Control Protocol/Internet Protocol (TCP/IP), also established the groundwork for what would one day supercede ARPAnet. TCP/IP replaced NCP in 1983, allowing ARPAnet to be connected with a variety of other networks that had since been launched. This group of networks evolved into what later became known simply as the Internet.

Several other key technologies emerged from various efforts to tweak ARPAnet. For example, e-mail capabilities, first introduced by Ray Tomlinson, were added to ARPAnet in 1971. Online discussion groups sprang up a short while later from address lists of e-mail users with common interests. Although the U.S. Department of Defense disbanded ARPAnet in 1990, its effects on online communications in the late 20th and early 21st centuries were immeasurable.