Agent-based computing is a promising approach for developing applications in complex domains. However,despite the great deal of research in the area, a number of challenges still need to be faced to make agentbasedcomputing a widely accepted paradigm in software engineering practice, and to turn agent-orientedsoftware abstractions into practical tools for facing the complexity of modern application areas. In thispaper, after a short introduction to the key concepts of agent-based computing and to the state of the art inthe area, we try to identify a few key open research directions.