JOSM

JOSM is a Java‑based editor for OpenStreetMap that runs on macOS, Windows, Linux and other platforms. It loads OSM data from local files or online services, displays background imagery, and supports GPX track import. Users can create and modify nodes, ways, and relations, as well as edit their metadata tags, while the interface offers a help system accessible via F1 or a dedicated button.

The editor is extensible through plugins that add functionality such as preset tag selections, rule‑based data validation, custom map styles, and additional background sources. These extensions can be installed from within the program, allowing users to tailor the tool to specific mapping workflows.

JOSM is open source under the GPL and receives regular updates, with stable releases distributed as JAR files, platform‑specific installers, and via package managers like Homebrew. Documentation, community support, and a bug‑reporting system are provided through the project’s website and OpenStreetMap forums.