Coral Content Distribution Network   (link)

http://www.coralcdn.org/
Publishing through Coral is as simple as appending a short string to the hostname of objects' URLs; a peer-to-peer DNS layer transparently redirects browsers to participating caching proxies, which in turn cooperate to minimize load on the source web server. Sites that run Coral automatically replicate content as a side effect of users accessing it, improving its availability. Using modern peer-to-peer indexing techniques, Coral will efficiently find a cached object if it exists anywhere in the network, requiring that it use the origin server only to initially fetch the object once.