EXOSAT was the first of ESA's scientific satellites to receive funding for a post-operational phase (from Jan 1986 to Dec 1990) to support the scientific community wishing to exploit the archival EXOSAT data. A major part of this activity has been the development of an on-line database containing standard data products and results from the mission. This database and its associated operating system provides astronomers with a powerful new tool for efficiently accessing and analysing large volumes of data.