This portal is about source code and compilation steps.

Knowledge of Java is not necessary, some portions of the code are explained in comments. You can inspect single files over the web frontend at svn (or browser).

Get the source

• From the official Subversion repository (recommended if you're interested in JOSM core only):

  svn co https://josm.openstreetmap.de/svn/trunk josm
  

• From the official OSM Subversion repository (recommended if you're also interested in plugins):

  svn co https://svn.openstreetmap.org/applications/editors/josm
  

• From the unofficial ​GitHub mirror:

  git clone git://github.com/openstreetmap/josm.git