This report describes work in progress to initiate the collaborative development of a new software platform for discrete-event simulation studies, the Open Simulation Architecture (OSA). OSA is primarily designed to be a federating platform for the simulation community: it is designed to favour the integration of new or existing contributions at every level of its architecture. This report describes the way OSA provides an open platform intended to support simulationists in a wide set of their simulation activities, and how it favours the reuse and sharing of system models by means of a flexible component model (Fractal). Indeed, OSA supports component-based modeling, which has many well-known good properties. Out of these properties is the ability to dispatch the modeling effort amongst several experts each having their own area of system expertise. Clearly, the less experts have to care about areas of expertise of others, the more efficient they are in modeling sub-systems in their own area. Furthermore, the process of studying complex systems using discrete-event computer simulations involves several areas of non-system expertise, such as discrete-event techniques or experiment planning. In OSA, all these tasks are clearly separated by identifying different kinds of (virtual) users: experimenters, developpers, model architects, and so on. OSA shall eventually supports each of these users by integrating dedicated tools for each of their specific tasks.