F or years, Sun Microsystems has beaten on the same drum. Since 1982, their corporate motto has been “the network is the computer.” However prescient this statement seems now, until a few years ago when the Internet, and especially the Web, really took off, it seemed like a hopeless abstraction to most people. Today, however, it seems that Scott McNealy was right, and the proof has come from the most unlikely places. Computers had only existed for a few years when people realized that linking them would multiply their power. Around the same time, it became obvious that we weren’t using some com- puters all the time. Because they were expensive devices, both to obtain and maintain, the indus- try saw these unused CPU cycles as an important waste of resources. The first time-sharing comput- ers were built in the early 1960s to address the wasted cycles problem and to make it easier to use computers without actually being in the room. Systems from Digital Equipment and IBM were hacked together to make it possible for several peo- ple to share one expensive computer. A descendent of these early networking attempts, peer-to-peer (P2P) networking via the Internet, is poised to become a killer app. First demonstrated as a way to share (some people say to steal) music, innovators are also using this tech- nology in more serious ways. Let’s take a look at how P2P technology is changing the way people work and play. New networking paradigms emerge In the mid-1990s, AppleTalk and Microsoft’s problematic Windows for Workgroups made P2P networks possible. Neither was a perfect solution, with AppleTalk (introduced in 1984) running on a serial protocol that limited speed and Windows for Workgroups being one of the buggiest operat- ing systems in memory. But both led the way to inexpensive networking that was ideal for small and home offices. For the first time, small offices could have some of the advantages of a LAN, such as sharing printers and files, without the expense and overhead of a network server. Not only was the capital cost reduced considerably, but in the- ory at least, network management was simple and undemanding—with AppleTalk that was true. Another new concept in networking, the Web, was a way to use the Internet to share hypertext documents among computers. It was developed in 1992 as a way for scientists at the European nuclear research lab, CERN, to collaborate. The developer of the protocols, Tim Berners-Lee, and the student who developed the first browser (in 1994), Marc Andreesen, soon became folk heroes. The Hypertext Transfer Protocol (HTTP) and the Mosaic browser, made possible an old dream of Ted Nelson’s—universally viewable and shareable hypertext documents—that he had labored on since 1960 under the name Xanadu. One of the Web’s unanticipated benefits was getting people to think about how to use networks of hundreds of thousands or even millions of com- puters. As Nelson realized, such a milieu could pro- vide a source of nearly infinite knowledge. Isn’t it likely that among the millions who cruise the Web every day we can find the answer to virtually any question? Furthering that idea, we can assume that virtually any file or bit of information that exists is on a computer hard disk on a machine connect- ed to the Internet. Going even a step further, how many CPU cycles are wasted every day between key strokes and while computers sit idle, waiting for something to do? When we stop to consider these possibilities, the mind boggles. It was thinking like this that helped David Gedye and Craig Kasnoff develop a way to use those wasted CPU cycles. Interested in the search for extraterrestrial intelligence (SETI), they conceived SETI@home in 1996 (see Figure 1). They raised money and found computers, and on 13 May 1999, they officially launched SETI@home from a lab on the University of California, Berkeley, campus. The system uses wasted CPU cycles by providing a light- weight client that runs in the background or as a 2 1070-986X/01/$10.00 © 2001 IEEE Multimedia at Work Editors: Tiziana Catarci and Thomas D.C. Little Ben Delaney CyberEdge Information Systems The Power of P2P