GPS log file viewer and analyzer
Viking is a free/open source program to manage GPS data
GPS track editor for editing tracks and planning (multiple) day tours
Tool to work on map data, to check the data and generate your own maps
Plugins for OpenCPN
GPS mapping and management software
A tile-based map viewer with support for GPX files.
Using PHP-CLI to parse NMEA data to generate depth maps with GD
a free and open map of wireless communicating objects