This book presents revised full versions of papers contributed to UK Workshops on Multi-Agent Systems, UKMAS, during 1996 and 2000.From the early days of MAS research, the UK community has been a particularly productive one with numerous key contributions.

Coordinating Intelligent Agents.- Strategies for Discovering Coordination Needs in MultiAgent Systems.- Agent-Mediated Interaction. From Auctions to Negotiation and Argumentation.- Game Theory and Artificial Intelligence.- Rights for Multi-agent Systems.- Infrastructure Support for Agent-Based Development.- An Anthropological Approach to the Discovery of Ontologies in Multi-agent Societies.- Scalability in Multi-agent Systems: The FIPA-OS Perspective.- Agents and MAS in STaMs.- Semantics of Agent Communication: An Introduction.- Agents with Bounded Temporal Resources.- A Model of Delegation for Multi-agent Systems.- Agent Specification Using Multi-context Systems.- An Adaptive Choice of Messaging Protocol in Multi Agent Systems.- On Partially Observable MDPs and BDI Models.