The next generation of tools for embedded systems design will represent a common arena for several cooperating groups. These tools will permit system design at a high abstraction level and enable automatic refinement through several abstraction levels to obtain the final prototype. To facilitate this evolution, we propose a new .Net Framework based system level modeling and simulation environment. This environment allows (1) cooperation -- by enabling web-based design and multi-language features, (2) easy systems specification task -- by enabling the integration of software components and by alleviating memory management and (3) the linking to automatic refinement tools -- by enabling the translation of model specifications into a standard intermediate format and by permitting the annotation of model specifications.