European Virtual Observatory (VO) activities have been coordinated by a series of projects funded by the European Commission. Three pillar were identified: support to the data providers for implementation of their data in the VO framework; support to the astronomical community for their usage of VO-enabled data and tools; technological work for updating the VO framework of interoperability standards and tools. A new phase is beginning with the ASTERICS cluster project. ASTERICS Work Package "Data Access, Discovery and Interoperability" aims at making the data from the ESFRI projects and their pathfinders available for discovery and usage, interoperable in the VO framework and accessible with VO-enabled common tools. VO teams and representatives of ESFRI and pathfinder projects and of EGO/VIRGO are engaged together in the Work Package. ESO is associated to the project which is also working closely with ESA. The three pillars identified for coordinating Europaen VO activities are tackled.