The VizieR database of astronomical catalogues

VizieR is a database grouping in an homogeneous way thousands of astronomic al catalogues gathered for decades by the Centre de Donnees de Strasbourg ( CDS) and participating institutes. The history and current status of this l arge collection is briefly presented, and the way these catalogues are bein g standardized to fit in the VizieR system is described. The architecture o f the database is then presented, with emphasis on the management of links and of accesses to very large catalogues. Several query interfaces are curr ently available, making use of the ASU protocol, for browsing purposes or f or use by other data processing systems such as visualisation tools.