GPSBabel

Marble   (Compare Project)

Mostly written in C++

License: lgpl

vlkGPS   (Compare Project)

Mostly written in Java

License: Unknown

MyTourbook   (Compare Project)

License: gpl

WherUGo   (Compare Project)

Mostly written in C#

License: gpl3

OpenStreetMap   (Compare Project)

License: Unknown

JOSM   (Compare Project)

Mostly written in Java

License: gpl

GeoServer   (Compare Project)

Mostly written in Java

License: gpl

Merkaartor   (Compare Project)

Mostly written in C++

License: gpl

Navit   (Compare Project)

Mostly written in C

License: gpl

OSM2Go   (Compare Project)

Mostly written in C++

License: gpl, gpl3_or_later