In this work we present the basic concepts for a dynamic plug-in-based software architecture using concepts from the Petri netbased MAS framework Mulan. By transferring the concepts of agentorientation to a plug-in-based architecture we are able to design our application and the plug-in-based system on an abstract level. Moreover, general problems that evolve from a highly dynamic and configurable architecture have been solved by basing the conceptual design on multi-agent principles. In this paper we discuss the general properties of extensible systems and the benefits that can be achieved when applying the multi-agent view to their architecture. In addition to the conceptual modeling of such architectures, we provide a practical example where the concept has been successfully applied in the