International audienceThe diversity of the distributed information sources and their heterogeneity is one of the main difficulties met by Web users today. The infrastructure of the semantic Web should allow their integration giving the illusion that he uses an homogeneous system. Solutions to integration in the setting of the semantic Web will benefit from research in mediator systems and data warehouses. The first achievements are under development. One of the first scientific challenges to be addressed is Web scalability. Future research work must focalize on decentralized mediation systems, the study of problems arising when integrating multimedia data, real-ti...