I'm familiar to this paper because I was using eMule. eMule has a direct citation to this paper in its "help" window, otherwise, the decentralization of eD2k would not be possible. The protocol is old, but still impressive.<p>The year 2000 is special, within the same year, Gnutella, eDonkey and Freenet were all released its initial version, as if the P2P network "emerged" from the Internet. By 2004, eMule, I2P and BitTorrent (and BTW, Tor) were all here. At the very beginning, the first generation of P2P, Gnutella was suffering from its scalability problem - its simple unstructured, flooding protocol needs a number of O(n) queries, and becomes unstable once the users exceeded millions.<p>Then, Kademlia almost saved P2P. BitTorrent, I2P, eD2k and many other P2P protocols are all Kad-based. For example, in eD2k, Kad allowed it to have P2P resource discovery, and also an efficient decentralized keyboard search engine (although there is spam, but mostly works, and in BitTorrent we still don't have it), all with only a O(log(n)) query, The P2P mechanism of I2P is also exclusively based on Kad.<p>The authors of this paper are the few people who have made great contributions to the Internet.