Viking is a free/open source program to manage GPS data
GPS log file viewer and analyzer
Simple GPS tracking server
GPS track editor for editing tracks and planning (multiple) day tours
A Matlab software to estimate Euler pole parameters
Open source system for GPS tracking devices
NMEA 0183 library for Java
Tool to work on map data, to check the data and generate your own maps
Plugins for OpenCPN
A software gps simulator
GPS mapping and management software
CAD 2D for Land Surveying and Civil
Open Source Marine Chart Plotting Program
This is a port of LibRTK on C#, and into a small c/c++ library.
Satellite Emulator