agent and multiagent concepts offer higher level abstractions and mechanisms which address issues such as knowledge representation and reasoning, communication, coordination, cooperation among heterogeneous and autonomous parties, perception, commitments, goals, beliefs, and intentions all of which need conceptual modeling. the aose 2005 workshop sought to examine the credentials of agent-based approaches as a software engineering paradigm, and to gain an insight into what agent-oriented software engineering will look like, and what its benefits will be. this book represents the thoroughly refereed post-proceedings of the 6th international workshop on agent-oriented software engineering, aose 2005, held in utrecht, the netherlands, in july 2005 as part of aamas 2005. the 18 revised full papers were carefully selected from 35 submissions during two rounds of reviewing and improvement. the papers are organized in topical sections on modeling tools, analysis and validation tools, multiagent systems design, implementation tools, and experiences and comparative evaluations.