Geographic library
Viking is a free/open source program to manage GPS data
GDAL wheels for python and C/C++ projects (Linux only)
Analysis and display of Census, business, government attribute data
Geodesy based library (geodetic and geocentric functions)
Multiplatform Ham Radio APRS and Mapping Program
MeteosatTool is for visualization and processing meteo satellite image
Tool-Kit aplication for system Geo Integrations