Interface Message Processor
1969
Bolt, Beranek and Newman, Inc., United States

The Interface Message Processor (IMP) was the first packet router for the ARPANET, the predecessor of today’s Internet. Inside was a Honeywell 516 minicomputer with only 6,000 words of software to monitor network status and gather statistics. The first ARPANET transmission occurred between the University of California in Los Angeles and Stanford Research Institute in Menlo Park, California, at 22:30 PST on October 29, 1969.

Memory Type: Core Speed: 520,833 Add/s Memory Size: 12K Cost: $82,200 Memory Width: (16-bit)

UCLA IMP logbook entry showing the first connection between two host computers over the ARPANET, October 29, 1969
Credit: UCLA

When the Soviet Union launched the Sputnik satellite in 1957, the US government responded with dramatically increased support of technology research and development, much of it funded through the new Advanced Research Projects Agency (ARPA).

In 1966 Bob Taylor of ARPA’s computer research division obtained funding for a network called ARPANET to link computers so that resources and results could be shared more easily. He hired Larry Roberts of MIT to manage the project, which was based on newly-invented packet-switching technology. At the end of 1969 the ARPANET began operating with four nodes: University of California at Los Angeles and Santa Barbara, Stanford Research Institute, and University of Utah. That original ARPANET gradually grew into the Internet, which 30 years later had about 43 million nodes.

The early Internet, used primarily by engineers and scientists, was not at all user-friendly. As e-mail and file transfer protocols and programs matured, non-specialists started to use it. In 1989, Tim Berners-Lee of the CERN high-energy physics lab in Europe proposed a protocol for the exchange of online documents which became the basis for the World Wide Web. The development in 1993 of the graphical browser Mosaic by Marc Andreesen and his team at the National Center For Supercomputing Applications (NCSA) made the web accessible to everyone and led to its explosive growth.

Marc Andreesen and entrepreneur Jim Clark founded Netscape in 1994 to create a web browser based on the Mosaic project. Netscape Navigator quickly dominated the early browser market.