We give a general overview of the European Esprit project, CONCERTO (CONCEptual indexing, querying and ReTrieval Of digital documents, P29159, URL: http://concerto.pira.co.uk/). The central idea of CONCERTO is to represent the 'meaning' of digital documents, making use of their associated 'conceptual annotations'; a conceptual annotation is intended to supply a computer-usable description of the main information elements of the whole document or of a part of it. We describe the general architecture of the CONCERTO Knowledge Engineering Software Environment (KESE).