Section I: Semantics of Agent Communication -- An Operational Model for the FIPA-ACL Semantics -- Temporal Logics for Representing Agent Communication Protocols -- ACL Semantics Between Social Commitments and Mental Attitudes -- On the Semantics of Conditional Commitment -- Section II: Commitments in Agent Communication -- A Commitment-Based Communicative Act Library -- Integrating Social Commitment-Based Communication in Cognitive Agent Modeling -- Flexible Conversations Using Social Commitments and a Performatives Hierarchy -- Using Social Commitments to Control the Agents’ Freedom of Speech -- Practical Issues in Detecting Broken Social Commitments -- Introducing Preferences into Commitment Protocols -- Section III: Protocols and Strategies -- On the Study of Negotiation Strategies -- Strategies for Ontology Negotiation: Finding the Right Level of Generality -- Combining Normal Communication with Ontology Alignment -- Towards Design Tools for Protocol Development -- Adaptiveness in Agent Communication: Application and Adaptation of Conversation Patterns -- Can I Please Drop It? Dialogues About Belief Contraction -- Commitment-Based Policies in Persuasion Dialogues with Defeasible Beliefs -- Section IV: Reliability and Overhearing -- Reliable Group Communication and Institutional Action in a Multi-agent Trading Scenario -- A Fault Tolerant Agent Communication Language for Supporting Web Agent Interaction -- Experiments in Selective Overhearing of Hierarchical Organizations.

Although everyone recognizes communication as a central concept in mul- agents, many no longer see agent communication as a research topic. Unf- tunately there seems to be a tendency to regard communication as a kind of information exchange that can easily be covered using the standard FIPA ACL. However, the papers in this volume show that research in agent communication is far from ?nished. If we want to develop the full potential of multi-agent s- tems, agent communication should also develop to a level beyond parameter or value passing as is done in OO approaches! In this book we present the latest collection of papers around the topic of agentcommunication.Thecollectioncomprisesofthebestpapersfromtheagent communication workshops of 2005 and 2006, enriched with a few revised agent communication papers from the AAMAS conference. Due to some unfortunate circumstances the proceedings of the 2005 workshop were delayed, but it gave us the opportunity to join the best papers of the 2006 edition to this volume. Together these papers give a very good overview of the state of the art in this areaofresearchandgiveagoodindicationofthetopicsthatareofmajorinterest at the moment.