Viking is a free/open source program to manage GPS data
Minimalistic wide-open GPS-locator/tracker
Create, edit view GPX tracks (in the background - online maps)
A C library for parsing/normalizing street addresses around the world
Plugins for OpenCPN
A library to generate short codes
A reference implementation of the Polish geobotanical grid
CAD 2D for Land Surveying,Civil and more
GT2 combines online and offline navigation for hikers and cyclists
a free and open map of wireless communicating objects