The Internet popped the cork in celebration of its 20th anniversary on New Year's Day.

In 1983, the Department of Defense's Advanced Research Projects Agency Network (ARPANET) officially switched from the Network Control Program (NCP) protocol to Transmission Control Protocol/Internet Protocol (TCP/IP). Six months later, ARPANET was split into two subnetworks--ARPANET, which would continue to serve researchers and eventually be renamed as the Internet, and MILNET, a network the military used to share unclassified information.

The original ARPANET had only a single network address, says Robert Braden, a project engineer for the University of Southern California's Information Sciences Institute. "When you split that address using TCP/IP, you could add more computers to the network connected by routers," says Braden, who wrote the TCP/IP code for UCLA's IBM mainframe in preparation for the 1983 switchover.

"This was the beginning of the ability to connect different networks together." The launch of the Internet heralded a new way of looking at computers--as communications devices rather than simply as number crunchers.