I enjoyed reading about Chord, and I'm impressed by the ideas behind Distributed Hash Tables. This area of research seems to be less than 10 years old, but as far as I can tell, there are dozens of different DHT designs and systems. In trying to make sense of all of this, I came across a recent 24-page survey that covers both design and applications, named appropriately Distributed Hash Tables: Design and Applications.
It seems like a great intro, but I feel like I'm missing something. As far as I can tell, CAN, Chord, Pastry, and Tapestry were all introduced about the same time in 2001, and Kademlia came out a year later. I still haven't read enough to know whether one is much better than the others. If one had been introduced a year earlier than the others, would there still be as many, or would the others just built on the work of the predecessors?