This book constitutes the thoroughly refereed post-proceedings of the Third International Workshop on Programming Multi-Agent Systems, ProMAS 2005, held in Utrecht, The Netherlands in July 2005 as an associated event of AAMAS 2005, the main international conference on autonomous agents and multi-agent systems. The 14 revised full papers presented together with 2 invited articles are organized in topical sections on multi-agent techniques and issues, multi-agent programming, and multi-agent platforms and organization.

Invited Papers.- MetateM: The Story so Far.- Agent-Based Computing and Programming of Agent Systems.- Multi-agent Techniques and Issues.- Dynamic Self-control of Autonomous Agents.- Bridging Agent Theory and Object Orientation: Importing Social Roles in Object Oriented Languages.- Implementation Techniques for Solving POMDPs in Personal Assistant Agents.- Using a Planner for Coordination of Multiagent Team Behavior.- Reusable Components for Implementing Agent Interactions.- Multi-agent Programming.- An AgentSpeak Meta-interpreter and Its Applications.- Extending the Capability Concept for Flexible BDI Agent Modularization.- A Model-Based Executive for Commanding Robot Teams.- Hermes: Implementing Goal-Oriented Agent Interactions.- Multi-agent Platforms and Organisation.- Organization and Mobility in Mobile Agent Computing.- Programming MAS with Artifacts.- Programming Deliberative Agents for Mobile Services: The 3APL-M Platform.- Implementing Multi-agent Systems Organizations with INGENIAS.- Declarative Agent Programming Support for a FIPA-Compliant Agent Platform.