OpenGTS (Open Source GPS Tracking System) is a full featured web-based GPS tracking system for your fleet of vehicles. It supports OpenLayers and other map providers, detail/summary Reporting, and various GPS tracking devices.
Viking is a free/open source program to manage GPS data. You can import, plot and create tracks, routes and waypoints, show OSM, Bing Aerial and other maps, geotag images, see real-time GPS position (not in Windows), make maps using Mapnik (not in Windows), control items, etc. It is written in mostly in C (with some C++) & the GTK+2 toolkit.
Client software for users of the Automatic Packet Reporting System amateur radio network.
Multiplatform Ham Radio APRS and Mapping Program
NOTE: Code commits are FROZEN on SourceForge: New code is now at <http://github.com/Xastir/Xastir>. Real-time tracking & messaging of stations via radio/internet APRS data streams, w/125 map formats supported. Linux/FreeBSD/Solaris/MacOSX/Windows in any of 7 languages. Can also be used for mobile mapping w/GPS. MAILING LISTS ARE AT: PROJECT->WEB SITE.
EDAS2 is a web-based environmental quality data management and decision support framework
G2C (Geospatial to Civil) The LandGML Interoperability Experiment initiated by Autodesk, U.S. Army Corps of Engineers Engineering Research and Development Center, and Galdos Systems. this open source tool transforms LandGML into LandXML documents.
Gpsdrive is a car (bike, ship, plane) navigation system. Displaying your position on a map and a lot of other functions are implemented. It works with vector maps from http://www.OpenStreetMap.de/