The design of complex real-time systems -in our case an autonomous mobile robot [1] -is particularly demanding with respect to hardware and software prototyping. In this paper, we focus on the software aspect. Software prototyping is required if new techniques, methodologies or approaches come into play. Their novelty usually calls for new tools. In addition, this prototyping has to be performed under hard time constraints due to time-to-market requirements. In previous work [2][3], we already presented that model-based generative prototyping allows to construct new design tools from scratch very fast and effectively using our prototyping environment APICES. We demonstrated this -among others -by way of Dual Dynamics Designer, a tool for behavior-oriented robot software synthesis. In this paper, we focus on two fields of important problems of software prototyping: integration of prototypes into design environments and evolution of prototypes from first solutions towards full-fledged design tools.The first problem is the integration of the prototype into a design environment which has to be taken into account very early in the course of the design process in order to achieve integrated solutions. A crucial question that has to be answered is how to construct and maintain the prototype interfaces to other tools within a design environment. In this paper, we introduce LQWHJUDWLRQ FODVVHV They provide a model-based specification, implementation and customization strategy for prototype interfaces.The second aspect we discuss is the evolution of our prototypes. The inherent problem with tools for new approaches such as Dual Dynamics [4] is that there is no design experience available for these tools. Development directions, design problems and the exact functionality of the new tool are not known in advance. These factors evolve over time and are strongly influenced by pilot users working with early prototypes of the new tool. The problem is even more complex in a design environment which has to be kept running while its tools are continuously changing. In this paper, we show how -in conjunction with explicit interface modeling -our prototyping approach facilitates incremental design and allows to develop prototypes step by step without impairing a productive design environment. This paper is structured as follows. Section 2 gives a short introduction and overview of Dual Dynamics Designer which we use as our example. Section 3 describes how DD-Designer is embedded in our design environment for robot software. Section 4 introduces LQWHJUDWLRQ FODVVHVour approach to integrate the prototypes into design environments. Section 5 shows how our methodology supports the evolution of prototypes. Section 6 discusses results and puts our work into perspective to related work. In conclusion, the paper gives a brief outlook towards future work.'XDO '\QDPLFV 'HVLJQHUThe Dual Dynamics (DD) scheme [4] is a mathematical model of a behavior system for autonomous mobile robots. It has grown from three roots: the behavior-based approach ...