Viking is a free/open source program to manage GPS data
GPS log file viewer and analyzer
Create, edit view GPX tracks (in the background - online maps)
Plugins for OpenCPN
GPS mapping and management software
Open Source Marine Chart Plotting Program
This is a port of LibRTK on C#, and into a small c/c++ library.
Land survey field crew data management for .RAW and .JOB file types.
A tile-based map viewer with support for GPX files.
Toolbox for geoscientists and geo enthusiasts
A software to manipulate RINEX 3 files
A gui for linux users of miniHomer, a GPS tracker
FAA digital chart viewer for iPhone and iPad
Aircraft navigator with HSI for TomTom devices
Plugin for OpenCPN
A program to convert different GPS date formats.
Analyze gpx files and store summary in Sqlite database
compeo++ - Manage Flytec/ Bräuniger Instruments
GPSBabel converts and transfers data like waypoints, tracks & routes.