Constitutes the refereed proceedings of the 4th German Conference on Multiagent Systems Technologies, MATES 2006, co-located with Net.ObjectDays (NoDe 2006). This book presents 15 revised full papers that are organized in topical sections on agent communication and interaction, applications and simulation, agent planning, and more.

Agent Communication and Interaction.- Adding New Communication Services to the FIPA Message Transport System.- Analysis of Multi-Agent Interactions with Process Mining Techniques.- Engineering Agent Conversations with the DIALOG Framework.- Agents’ Bidding Strategies in a Combinatorial Auction.- Applications and Simulation.- Modeling and Simulation of Tests for Agents.- Agent-Based Simulation Versus Econometrics – from Macro- to Microscopic Approaches in Route Choice Simulation.- Agent Based Simulation Architecture for Evaluating Operational Policies in Transshipping Containers.- Agent Planning.- Diagnosis of Multi-agent Plan Execution.- Framework and Complexity Results for Coordinating Non-cooperative Planning Agents.- Agent-Oriented Software Engineering.- A Model Driven Approach to Agent-Based Service-Oriented Architectures.- Meta-models, Models, and Model Transformations: Towards Interoperable Agents.- Formation of Virtual Organizations Through Negotiation.- Continuations and Behavior Components Engineering in Multi-Agent Systems.- Trust and Security.- Evaluating Mobile Agent Platform Security.- A New Model for Trust and Reputation Management with an Ontology Based Approach for Similarity Between Tasks.