ModelAge will gather experts from each of the fields mentioned above, selected for their ability to bring important and rigourous innovations in their field. Systematic interdisciplinary cross-fertilisation exchanges will be organized. This type of cross-fertilisation, performed in an non-systematic way by members of the group, has lead to important new applications in each field. The long-term goal is to establish a common formal model, that seems suited to the needs of each field. Classical formalisms in each field will be given a semantic definition in terms of the common model. Then the most promising of these languages will be extended to make full use of the richness of the underlying model. The definition of a general purpose common language is not among the objectives of ModelAge.