JOSM is an extensible editor for ​OpenStreetMap (OSM) in ​Java.

It supports loading GPX tracks, background imagery, and OSM data from local sources as well as from online sources and allows to edit the OSM data (nodes, ways, and relations) and their metadata tags.

JOSM is translated by the community in more than 40 languages.

It is open source and licensed under GPL​: https://josm.openstreetmap.de/