This paper introduces to the reader the field of cooperating intelligent software agents. It first reviews the historical roots of Distributed AI, and the main concepts that have been developed in that field since the end of the seventies, and on which today’s agent technology is based upon. The paper then concentrates on the modeling of agents. Starting with a terminological discussion of what agents are, and with an example the main characteristics of cooperating intelligent agents are presented, formalized, and discussed. Based upon this the paper proceeds to issues that are relevant to multiagent systems: coordination, communication, and standardization. The paper concludes with a sum-up of the main results, and an extensive bibliography.