Jury. Président : Michel COSNARD Rapporteurs : Bertil FOLLIOT, Jean-Marc GEIB Membre du jury : Henri BAL Directeurs de thèse : Thierry PRIOL, Christian PEREZIn this thesis, we study a communication platform model for computational grids. We aim at extending the scope of grids by allowing to run parallel and/or distributed applications without imposing any particular middleware or programming constraint. The proposed model allows the use of various middleware, adapted by the application rather than dictated by available networking resources. Our approach is based on : resources access arbitration, to allow several middleware simultaneously; abstraction adapters, to see the resources with a paradigm chosen by the user; resources virtualizatio...