This review paper discusses the industrial and research activities around the IEC 61499 architecture for distributed automation systems. IEC 61499 has been developed to enable intelligent automation where the intelligence is genuinely decentralized and embedded into software components, which can be freely distributed across networked devices. With the recent emergence of professionally made software tools and dozens of hardware platforms, IEC 61499 is getting recognition in industry. This paper reviews research results related to the design of distributed automation systems with IEC 61499, the supporting tools and the aspects related to the execution of IEC 61499 on embedded devices. The promising application areas of IEC 61499 include flexible material handling systems, in particular airport baggage handling, flexible reconfigurable manufacturing automation, intelligent power distribution networks and SmartGrid, as well as the wide range of embedded networked systems.