APEX will be the follow-up of the APEnet project, in which national archival institutions from 14 European countries have realised – in collaboration with Europeana – the Archives Portal Europe, the first version of an internet portal for documents and archives in Europe and an archives aggregator for Europeana. APEX aims at widening, deepening, improving and sustaining this initiative, thus expanding in quality as well as quantity the delivery of digital archival content to Europeana. This goal comprises actions in various domains:•\tExpansion of the network of contributing archival institutions in Europe itself,•\tSubstantial improvements in the interoperability with Europeana,•\tStabilisation of the Archives Portal Europe portal infrastructure & hosting and improvement of its throughput capacity, availability of more standards & guidelines as well as tooling & support to the content providers to help them deliver more content,•\tDissemination & training programmes to drive aggregation on the national level and raise awareness of archival content in Europe•\tInnovation in usability and Web 2.0 functionality to modernise content delivery•\tSustainability of this effort.In more detail APEX will take on board more European institutions (widening) and will help these institutions with aggregation on the national levels (deepening). APEX will work actively with the Europeana portal on interoperability of metadata formats and rights management of the archival material. All this will serve the main goal of preparing as much archival content of European institutions as possible to the Archives Portal Europe and channel the digitised and digital archival material therein to the Europeana portal.