Complex, heterogeneous, real time embedded applications require sophisticated developments tools for simulation and implementation. Commercial, closed source applications are available “on the shelf”, but the associated financial effort and the limited flexibility are not always compatible with the budget constraints and the technical specifications. Some specific requirements of the embedded applications match very well the intrinsic proprieties of the Open Source software. In this paper we show how Scilab/Scicos can play the role of an Open Source platform for embedded systems by presenting both its development model and its applications.