At the turn of our new century, during the heyday of Napster, the infotech conversation was all about peer-to-peer, or P2P, technology. There were elite gatherings of leading influentials to assess its potential, conferences to bring together ideas and money, new publications to chronicle its development.
In September 2000 Dave Winer wrote a touchstone essay called The P in P2P. “It’s not about P2P, specifically, that people should be getting excited,” Dave wrote. “The killer app of P2P is … People!”
When Groove 1.0 launched I was asked by a media producer to explain why Groove was an important P2P application. Channeling Dave, I said that Groove was important because it empowered people to work together effectively, not because it was a poster child for P2P.
Back then, we lacked the cloud infrastructure to support the loosely-coupled networks of personal services I imagined. But that infrastructure is emerging now. I see it, for example, in the P2P capabilities of Live Mesh.
Nowadays, of course, we rightly no longer regard P2P as a silver bullet. But the infotech tribe is wired to seize on some silver bullet, and so a new one is being loaded into the chamber. It bears an inscription: “the semantic web”.
For good reason! We experience, many times every day, the transformative power of search based on nothing more than the ability to ask and answer the question: “What document contains the word X?” Questions can be a whole lot more interesting than that, and answers can be a whole lot more useful.
On the semantic web, the notion is that queries will traverse ad-hoc collections of data in which the relationships among items of information — within and across datasets — are made explicit. To use the phrase that comes up again and again in these discussions, we’ll be able to “reason over” this web of linked datasets.
We’ll get there, I hope, but let’s not conflate means with ends. During the initial P2P craze we acted as if the P2P web was a goal. Today we see that it’s one of many architectural styles. We use it where appropriate, in concert with other styles, and we’re a bit clearer — I hope — that the killer apps are the ones people make when living and working in a networked world that includes the possibility of P2P.
So it will go with the semantic web, I predict. At the moment it seems like a goal, a grand challenge. And of course it is. But the killer apps will be those that people make when using — and here’s a twist, when creating — the semantic web.
That’s a key distinction. Users of the P2P web don’t, for the most part, build its enabling infrastructure. But users of the semantic web will. Yes, networked computers will weave the basic fabric of linked data. But we’ll need to do the context assembly that makes the semantic web useful to us.
We may be P2P’s killer app, but we’re going to be the kernel of the semantic web’s operating system. That’s why the engineering of that operating system will have to be as much social as technical, and maybe more so.