Viking is a free/open source program to manage GPS data
GPS log file viewer and analyzer
GPS track editor for editing tracks and planning (multiple) day tours
Open Source Desktop GIS with Surveying and Cartography Functionality
Create, edit view GPX tracks (in the background - online maps)
a simple virtual world editor
Offline vector map display ported from OsmAnd
eGPXviewer is a 3D GPX track viewer
Java Library for working with gpx files
GPS mapping and management software
Web Mapping Platform
A tile-based map viewer with support for GPX files.
Raster layer editing toolbar for ArcMap 10.x
Automate merging / importing of country data from different sources
Open Street Map (OSM) tools, OSM/XML parser, tag extractor
Convert a Garmin ADM database file to a GPX file