garmin_gpx man page
garmin_gpx — convert .gmn files into xml data for use with OpenStreetMap
garmin_gpx reads a .gmp file as produced by garmin_save_runs, and writes to standard output the xml representation (for OpenStreetMap maps).
garmin_get_info(1), garmin_save_runs(1), garmin_dump(1).
garmin_gpx was written by Chris AtLee.