||Nowadays, agents play an important role in computer science. The goal of this report is to show the wide spectrum of the different application domains where agent technology is currently used or can be used in the future. Especially, we cover applications in the telecommunication domain. For this purpose we describe four applications in more detail that use agent technology in telecommunication networks.Another important part of this report is to give the reader a historical overview of agent research activities. Because of the lack of an accepted definition for an intelligent agent we describe an intelligent agent by some characteristic properties. Furthermore, we classify existing software agents into several dimensions and describe different agent types.This paper describes an architectonic view of an agent. Finally, we introduce four well-known agent frameworks.