The realisation of a new atlas of colour-magnitude diagrams based on improved and homogeneous cluster parameters was the first scientific use of the database foreseen and the motivation of its development. The way to achieve this goal is however quite long, but it remains a major project. When reliable parameters have been determined for a number of clusters, it becomes possible to do some astrophysical research.
The information collected in the database may be used to study the clusters' stellar content and properties. In spite of the limitations due to the lower precision of some data, or their limited number, the database is the best starting point for many astrophysical studies involving open clusters. Nowhere are complete data collections to be found and one merit of the database is to give a clear report of the present observation status.
The database facilities have been used by Meynet et al. (1993) to compare new theoretical isochrones with the colour-magnitude diagrams of 30 clusters. In the spring of 1994, the database was successfully used to cross-identify the stars detected by the Tycho experiment on board the Hipparcos satellite.