Viking is a free/open source program to manage GPS data
GPS track editor for editing tracks and planning (multiple) day tours
Free minimalist software for maps, import DWG, DXF, SHP, KML, GeoJSON
a simple virtual world editor
Offline OpenStreetMap maps for iOS and Android
Raster layer editing toolbar for ArcMap 10.x
Automate merging / importing of country data from different sources