Abstract
This paper presents the idea that agents and environment play an equally important role in MAS design and proposes an architecture for agent environment system (AES). This architecture is based on software engineering concepts such as separation of concerns, modularity and information hiding. This leads to adaptable systems that can support multiple application domains. These concepts are illustrated through DIVAs, a geographically based social simulation tool, which offers flexibility without regulating simulation developers to a specific problem domain. The purpose of this paper is to introduce the motivations and concepts surrounding the AES architecture and show how DIVAs realizes the concepts of AES for one application domain.