Using filters with GPSBabel - OpenStreetMap Wiki
gpsbabel -i gpx -f in.gpx \ -x transform,wpt=trk,del \ -x radius,distance=1.1K,lat=40.01,lon=10.001,nosort,exclude \ -x transform,trk=wpt,del \ -o gpx -F out.gpx
GPX Waypoint Generation
oa2gm - airspace maps translator
GPX Aviation Waypoint Generation
many countries, many aviation waypoint types
FrontPage - Handhelds.org MoinMoin Wiki
Linux for PDAs
Happy Camel, match your GPS with your digital photographs
free GPS Software and mapping for navigation on Laptop, Pocket PC and Smartphone
windows only
GPS Visualizer
converts coordinates from GPS files and draws tracks etc onto Google Maps, Earth and jpegs etc creates maps
Cockpit and Small Boat GPS