  The Centre de Donnees astronomiques de Strasbourg (CDS) provides homogeneous
access to heterogeneous information of various origins: information about
astronomical objects in Simbad; catalogs and observation logs in VizieR and in
the catalogue service; reference images and overlays in Aladin; nomenclature in
the Dictionary of Nomenclature; Yellow Page services; the AstroGLU resource
discovery tool; mirror copies of other reference services; and documentation.
With the implementation of links between the CDS services, and with other
on--line reference information, CDS has become a major hub in the rapidly
evolving world of information retrieval in astronomy, developing efficient
tools to help astronomers to navigate in the world-wide `Virtual Observatory'
under construction, from data in the observatory archives to results published
in journals. The WWW interface to the CDS services is available at:
http://cdsweb.u-strasbg.fr/
