In part that depends on what you mean by “precursor” or “invented”, because several systems could claim that distinction. Online bulletin board systems, for instance. Or even packet radio, if your definition is a system which allowed people in disparate locations to communicate by typing on a terminal. But most people who remember a time before the Internet consider the answer to “What is the precursor to the Internet?” to be the ARPANET.
As Danny Goodman explains in his excellent book SpamWars, back in 1962 (yes, more than 40 years ago!), “experiments proved the concept of connecting computers to each other across a linkup originally using a regular telephone line. With much funding help through the U.S. Defense Department’s Advanced Research Projects Agency (ARPA), several universities and a few private corporations worked toward the goal of connecting multiple systems to allow researchers from one facility to run applications and access data at another facility in collaboration.”
While the concept was proven, it would be another 7 years before it was successfully put into effect, and then on a very limited basis.
“In 1969, the network built with ARPA funding, called ARPANET, successfully connected the first two, and then four, computers at different locations around the western United States,” explains Goodman. Those first four locations were educational sites in Los Angeles (UCLA) and Palo Alto (Stanford), and then Santa Barbara and Salt Lake City (University of Utah).
That was thirty-five years ago, back in 1969, but even though there was no turning back at that point, the evolution of connectivity went at a relative snail’s pace, and it would be another twenty years before the concept of regular people being able to communicate with other regular people outside of their own local computer systems was brought to the masses. That happened, according to Goodman, when MCI Mail became the first commercial computer service to offer the ability to send and receive email between two computer systems.
And now here we are, a mere sixteen years after MCI Mail’s initial offering, and most people who use the Internet can’t remember a time without email, without online shopping, instant messaging, and finding whatever information they need online.
But it all started, more than forty years ago, as an effort to allow academics to collaborate across the miles.
And if you are interested in this and more history and information about the Internet, you won’t find a more excellent resource than Goodman’s SpamWars.
source : http://www.theinternetpatrol.com