This book presents selected tutorial lectures given at the summer school on Multi-Agent Systems and Their Applications held in Prague, Czech Republic, in July 2001 under the sponsorship of ECCAI and Agent Link. The 20 lectures by leading researchers in the field presented in the book give a competent state-of-the-art account of research and development in the field of multi-agent systems and advanced applications. The book offers parts on foundations of MAS; social behaviour, meta-reasoning, and learning; and applications.