This book originates from the First International Workshop on Massively Multi-Agent Systems, MMAS 2004, held in Kyoto, Japan in December 2004. The 25 revised full selected and invited papers give an excellent introduction and overview on massively multi-agent systems. The papers are organized in parts on massively multi-agent technology, teams and organization, ubiquitous computing and ambient intelligence, and massively multi-agent systems in the public space.