Viking is a free/open source program to manage GPS data
... the open-source glide computer
A Guide of the Trees of Barcelona City
Build your own GPS unit
A C library for parsing/normalizing street addresses around the world
Whitestone Interactive GPS Software for .Net
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
GPSBabel converts and transfers data like waypoints, tracks & routes.