In this article, we present the development of research carried out to design a system of interactive scores for composition and execution, based on temporal constraints called Iscore. This system has been designed in order to allow musicians to interpret pieces of electro-acoustic music but since it uses a symbolic representations of the scores, it can bee seen as a system for more generally writing interaction with a temporal approach. Then, numerous other applications could be possible. This system can be used to create interactive multimedia scenarios (for theater shows or museum visits as examples) and also for adapting musical pieces or interactive multimedia documents for mutli-player applications or players with limited ability.