GDK(GEOMania Development Kit) is a Developmet Kit for GIS application S/W based component. If experienced programming using various components, it is possible for developing GIS application software easily in a short period of time. GEOMania Pro V3.0 and GEOMania Pro/3D V3.0 is already known for it's convenience and excellency, with a little effort and time it is possible to develop a stable and outstanding program