The Current Peer-to-Peer Meme MapThe meme map for peer-to-peer is still very unformed, and consists largely of ideas applied by the media and other outsiders.
Here's the slide I showed to the group at the summit. Things have evolved somewhat since that time, partly as a result of efforts like ours to correct common misconceptions, but this picture still represents the view being bandied about by industries that feel threatened by peer-to-peer technologies:
Current Peer-to-Peer Meme Map (Click to enlarge)
Not a pretty picture. The canonical projects all feed the idea that peer-to-peer is about the subversion of intellectual property. The chief benefit presented to users is that of free music (or other copyrighted material). The core competencies of peer-to-peer projects are assumed to be superdistribution, the lack of any central control point and anonymity as a tool to protect the system from attempts at control.
Clearly, these are characteristics of the systems that put the peer-to-peer buzzword onto everyone's radar. But are they really the key points? A map is useful only to the extent that it reflects underlying reality. A bad map gets you lost; a good one helps you find your way through unfamiliar territory.
The New Peer-to-Peer Meme MapOne major goal for the summit was to develop a better map for the uncharted peer-to-peer space. There is a cluster of technologies that we need to consider together in order to come up with an accurate picture of peer-to-peer and what is possible.
We spent a few hours brainstorming about important applications of peer-to-peer technology, key principles, and so on. I've tried to capture the results of that brainstorming session in the same form that I used to spark the discussion, as a meme map. Note that this is my personal take-away from the meeting. The actual map below wasn't fully developed or approved there.
New Peer-to-Peer Meme Map (Click to enlarge)
A quick walk through of the various projects and how they fit together leads us to a new understanding of the strategic positioning and core competencies for peer-to-peer projects. In the course of this walk-through, I'll also talk about some of the guiding principles that we can derive from studying each project, which are captured in the bubbles in the lower half of the diagram. This discussion is necessarily quite superficial, but suggests directions for further study.
File Sharing, and Lessons from NapsterOne of the most obvious things about the map I've drawn of the peer-to-peer space is that file-sharing applications, such as Napster, Gnutella and Freenet, are only a small part of the picture, even though they have received the lion's share of the attention. Nonetheless, Napster, as the application whose rapid uptake and enormous impact on the music industry sparked the furor over peer-to-peer, deserves some significant discussion.
One of the most interesting things about Napster is that it's not a pure peer-to-peer system in the way that radically decentralized systems like Gnutella and Freenet are. While the Napster data is distributed across millions of hard disks, finding that data depends on a central server. In some ways, the difference between MP3.com and Napster is smaller than it appears: one centralizes the files, while the other centralizes the addresses of the files.
The real genius of Napster is the way it makes participation automatic. By default, any consumer is also a producer of files for the network. Once you download a file, your machine is also available to pass along the file to other users. Automatic "pass along" participation decentralizes file storage and network bandwidth, but most importantly, distributes the job of building the Napster song database.
Dan Bricklin has written an excellent essay on this subject, The Cornucopia of the Commons. In this wonderful reversal of Hardin's tragedy of the commons, Bricklin explains why Napster demonstrates the power of collectively assembled databases in which "increasing the value of the database by adding more information is a natural by-product of using the tool for your own benefit.
This feature is also the source of Dave Winer's insightful comment that "The P in P2P is People."
Dave's comment highlights why the connection to the open-source movement is significant. Open-source projects are self-organizing, decentralized work groups enabled by peer-to-peer Internet technologies. If the P in P2P is people, then the technologies that allow people to create self-organizing communities, and the frameworks that have been developed for managing those communities, provide important lessons for those who want to work in the peer-to-peer space.
Open source isn't just about a set of licenses for software distribution, it's also a set of techniques for collaborative, wide-area software development. (This was one of the principles behind my call for organizing peer-to-peer standards activities, along the same lines as the self-organizing IETF, rather than as a centralized industry consortium.) As I've argued elsewhere, it was the peer-to-peer Usenet that was one of the key drivers of the early open-source community. Technologies that enable people to associate freely, end-to-end, are great levelers, and great hotbeds to promote innovation.
Napster also illustrates another guiding principle: that of redundancy, and tolerance of unreliability. I was talking recently with Eric Schmidt, CEO of Novell, about lessons from peer-to-peer. He remarked on a conversation he'd had with his 13-year-old daughter. "Does it bother you that sometimes songs are there, and sometimes they aren't?" "Does it bother you that there are lots of copies of the same song, and that they aren't all the same?" Her answer, that neither of these things bothered her in the slightest, seemed to him to illustrate the gulf between the traditional computer scientist's concern for reliability and orthogonality and the user's lack of care for these issues.
Another important lesson from Napster is that free riders, "super peers" providing more or better resources, and other variations in peer participation will ultimately decrease the decentralization of the system. Experience is already showing that a hierarchy is starting to emerge. Some users turn off file sharing. Even among those who don't, some have more files, and some have better bandwidth. As in Orwell's Animal Farm, all animals are equal, but some are more equal than others. While this idea is anathema to those wedded to the theory of radical decentralization, in practice, it is this feature that gives rise to many of the business opportunities in the peer-to-peer space. It should give great relief to those who fear that peer-to-peer will lead to the leveling of all hierarchy and the end of industries that depend on it. The most effective way for the music industry to fight what they fear from Napster is to join it, and provide sites that become the best source for high quality music downloads.
Even on Gnutella, the concept of super peers is starting to emerge. Clip2's DSS (Distributed Search Solutions) has developed a program that they call a Gnutella "Reflector," a proxy and index server designed to make Gnutella more scaleable. According to Kelly Truelove of Clip2, "Multiple users connect to such a Reflector as they might connect to a Napster central server, yet, unlike such a central server, the Reflector itself can function as a peer, making outgoing connections to other peers on the network."