Peer-to-peer networking is a disruptive technology for large scale distributed app- cations that has recently gained wide interest due to the successes of peer-to-peer (P2P) content sharing, media streaming, and telephony applications. There are a large range of other applications under development or being proposed. The - derlying architectures share features such as decentralizaton, sharing of end system resources, autonomy, virtualization, and self-organization. These features constitute the P2P paradigm. This handbook broadly addresses a large cross-section of c- rent research and state-of-the-art reports on the nature of this paradigm from a large number of experts in the ?eld. Several trends in information and network technology such as increased perf- mance and deployment of broadband networking, wireless networking, and mobile devices are synergistic with and reinforcing the capabilities of the P2P paradigm. There is general expectation in the technical community that P2P networking will continue to be an important tool for networked applications and impact the evo- tion of the Internet. A large amount of research activity has resulted in a relatively short time, and a growing community of researchers has developed. The Handbook of Peer-to-Peer Networking is dedicated to discussions on P2P networks and their applications. This is a comprehensive book on P2P computing.