The idea of writing this book, Peer to Peer: Collaboration and Sharing over the Internet, seemed in several ways a natural and complementary progression from the previous one, The Wiki Way (Addison-Wesley, 2001). Subtitled Quick Collaboration on the Web, that book explored the client-server peer-collaborative world of WikiWiki. In that server-centric situation, there were even then hints of a wider peer perspective for applications, for example interlinking different wiki servers in a peer-to-peer kind of network to transparently exchange content and extend search capabilities across multiple sites.
The main thrust of this book, however, is to explore what, at its extreme, becomes the complete opposite of server-centric communication: when individual user applications connect "end-to-end" with each other across the network for various purposes. One significant and popular reason for such connectivity is to share content (file swapping), but beyond that, the full potential lies in the broader purpose of communicating and collaborating between endpoint applications, as well as between the users who sit at their respective computers or carry the appropriate network-aware devices.