GpsPrune is a map-based application for viewing, editing and converting coordinate data from GPS systems.
It's a cross-platform java application, and its home page is at https://gpsprune.activityworkshop.net .
Here on github you'll find all the sources from version 1 to the current version 19, and in the wiki at https://github.com/activityworkshop/GpsPrune/wiki there's the beginning of a translation effort for anyone to contribute. Currently just the Spanish translations are online, to see whether it's a workable idea or not. Please help with this if you can.