The fast-growing area of web services offers the multi-agent community exciting research possibilities, including similarities in system architectures, powerful tools, and a focus on issues such as trust and reliability. This book contains contributions by leading international researchers and professionals from both the web services and Multi-Agent Systems (MAS) community, addressing the rapidly growing impact of Multi-Agent Systems on web services tools and techniques. The contributors also investigate the potential for MAS techniques to impact the difficult challenges that must be tackled for web services technology to realize its promises.