Starting with Napster and Gnutella, peer-to-peer systems became an integrated part of the Internet fabric attracting millions of users. According to recent evaluations, peer-to-peer traffic now exceeds Web traffic, once the dominant traffic on the Interne. While the most popular peer-to-peer applications remain file sharing and content distribution, new applications such as Internet telephony are emerging. Within just a few years, the huge popularity of peer-to-peer systems and the explosion of peer-to-per research have created a large body of knowledge, but this book is the first textbook-like survey to provide an up-to-date and in-depth introduction to the field. This state-of-the-art survey systematically draws together prerequisites from various fieds, presents techniques and methodologies in a principled and coherent way, and gives a comprehensive overview on the manifold applications of the peer-to-peer paradigm. Leading researchers contributed their expert knowledge to this...