Converts GPS waypoint, route and track data from one format type to another
http://www.gpsbabel.org/

GPSBabel converts waypoints, tracks, and routes from one format to another, whether that format is a common mapping format like Delorme, Streets and Trips, or even a serial upload or download to a GPS unit such as those from Garmin and Magellan. By flattening the Tower of Babel that the authors of various programs for manipulating GPS data have imposed upon us, it returns to us the ability to freely move our own waypoint data between the programs and hardware we choose to use.

It contains extensive data manipulation abilities making it a convenient for server-side processing or as the backend for other tools.

It does not convert, transfer, send, or manipulate maps. We process data that may (or may not be) placed on a map, such as waypoints, tracks, and routes.