This describes how to develop and [wiki:DevelopersGuide/Compiling compile] JOSM using [https://www.jetbrains.com/idea/ IntelliJ IDEA]

1. Getting the source Source → [[Download#Source]]
2. Run ant in the source directory to obtain a `josm-custom.jar` → [[DevelopersGuide/Compiling#CompilingusingAnt]]
3. In IntelliJ: File → New → Project from Existing Sources
4. …