C translation of EGM96 (earth height model) implementation (namely, f477.f) available at http://earth-info.nga.mil/GandG/wgs84/gravitymod/egm96/egm96.html
libTopo and TopoMap are tools to use, convert, analyze and display topography maps such as ETOPO2, ETOPO5 and GLOBE. TopoMap is the command line interface to convert topography databases to raw data, images, etc...