LaClef is a project aimed at finding ways of unlocking some of the valuable Geographic Information data held in the European public sector. It proposes to demonstrate how an effective pan-European, multi-sector service can be developed and successfully integrated. It will build on existing European initiatives, including MEGRIN's existing GDDD, to identify how an effective GI metadata and on-line data supply service can be developed. The service will use a sophisticated architecture to provide enhancements such as a multilingual interface to high level metadata across geographic information sectors such as topographical mapping, aerial imagery and geology. LaClef will also develop an e-commerce prototype model which will help identify the various implementation issues involved.