Viking is a free/open source program to manage GPS data
Plugins for OpenCPN
Build your own GPS unit
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.
Analyze and change GPS coordinates and time in digital pictures
Satellite Emulator
A tile-based map viewer with support for GPX files.
Toolbox for geoscientists and geo enthusiasts
Whitestone Interactive GPS Software for .Net
CAD 2D for Land Surveying,Civil and more
Plugin for OpenCPN
a free and open map of wireless communicating objects
GPS data in a file for development testing
PC/PocketPC tool to get tracklogs from the WBT-201 GPS logger