http://gpx.geotags.com/cgi-bin/gpx.cgi uses the gpx format. I thought maps.google.com/maps uses the kml format.

google.c calls map_kml_get_placemarks(kml) in kml.c;

In kml.c the following xml elements are handled:
[EL_KML] = "kml",
[EL_DOCUMENT] = "Document",
[EL_PLACEMARK] = "Placemark",
[EL_POINT] = "Point",
[EL_LINESTRING] = "LineString",
[EL_NAME] = "name",
[EL_DESCRIPTION] = "description",
[EL_COORDINATES] = "coordinates",
[EL_ALTITUDE_MODE] = "altitudeMode",