This book constitutes the refereed proceedings of the 4th German Conference on Multiagent Systems Technologies, MATES 2006, co-located with Net.ObjectDays (NoDe 2006). The 15 revised full papers presented were carefully reviewed and selected from 52 submissions. The papers are organized in topical sections on agent communication and interaction, applications and simulation, agent planning, agent-oriented software engineering, as well as trust and security.

The ATOP (Agent-Based Technologies and Applications for Enterprise Interoperability) workshop series focuses on technologies that support interoperability in networked organizations, on successful applications of these technologies, and on lessons learned. In particular, ATOP brings together research combining ideas from MDA and SOA with agent technologies. The ATOP 2009 and 2010 workshops were held at the AAMAS conferences in Budapest, Hungary, in May 2009, and in Toronto, Canada, in May 2010. The 11 papers presented here were carefully reviewed by three members of the international Program...