1. A method of externalizing legacy data from a legacy database on a data resource into a format compliant with a certain structured output format in which the format is specified by an associated, automatically generated meta-description, thus enabling access and processing of legacy data by applications that read the structured output format, the method comprising: an exploration/adaptation step for exploration of the data resource; and a production step for generation of the structured output format data out of the legacy data on the data resource.