Geographic library
Viking is a free/open source program to manage GPS data
An information system for cyclists in Berlin and Brandenburg
Toolkit for working with and mapping geospatial data
Geographic feature extraction and data mining
Open source system for GPS tracking devices
A GUI for the freeware Geographical Information System PCRaster
Plugins for OpenCPN
Geodesy based library (geodetic and geocentric functions)
Multiplatform Ham Radio APRS and Mapping Program
OTB is an open-source C++ library for remote sensing images processing
QNetMap is the library for displaying the map and the objects on it
Some pythons plugins to enhance fantasy maps creation with QGis
Geolocation Postcode Algorithm