The author of this book introduces the main issues of agent-oriented architectures and gives their solutions accompanied by practical examples. The explanations are based on similarities with issues and solutions in human organizations. Each of the main issues is discussed in a separate chapter. Firstly, the agent organization framework: decomposition, structures, organizational design activities, and an example (supply chain management) are presented. Then coordination strategies are discussed as problem solving techniques, their methods are classified, and implications to their design are deduced. The ‘five capabilities model’ is then described in its dimensions and then clarified on a complex insurance example. The chapter, ‘Interoperation within complex multi-agent strategies’, is based on experience with the IRBOW project. The chapter also concerns levels of interoperability with emphasis on the semantic one. The last chapter, ‘Message content ontologies’, recalls some useful ontologies and issues concerning ontology development and applications. The book may be useful for people willing to increase their understanding of agents and their coordination.