Viking is a free/open source program to manage GPS data
... the open-source glide computer
Tool to work on map data, to check the data and generate your own maps
Plugins for OpenCPN
GPS mapping and management software
CAD 2D for Land Surveying and Civil
This is a port of LibRTK on C#, and into a small c/c++ library.
CAD 2D for Land Surveying,Civil and more
Convert GPS-Tracks user-saved tracks to KML files for Google Earth.
GPSBabel converts and transfers data like waypoints, tracks & routes.