This is a report from the conference PV 2007, held at the German Remote Sensing Data Centre, DLR, Oberpfaffenhofen, on October 9–11, 2007. The PV conference is held every two years, and is concerned with the preservation of scientific and technical data, and the activity of adding value to the data to ensure it can be widely used and re-used. The theme for 2007 was 'the Challenge of Heterogeneity', not only in the data being supported but in the tools used to access and process the data, and in the uses to which the data may be put.