Download

• Note that there are fairly regular updates, so always try running a recent version (and also recent plugins).
• Access JOSM-WebStart without installation
• Download the tested JOSM version 5939
• Download the Windows JOSM installer version 5939
• Download the Mac OS X JOSM package version 5939
• Prepare a USB flash drive to use JOSM on any foreign Windows machine.
• For download scripts use version check for latest and tested (or both) to reduce download bandwith
• If download size is an issue for you, you may append ?lang=.. to the download link for both releases to strip all unused translations (e.g. ?lang=de would download JOSM in German language only).

Development Version

• Download the latest JOSM version 5966 (may have more errors than "tested", be careful with this one).

Applet

• Try JOSM applet after reading the applet description.

Source

• Get the source:
  • From the official Subversion repository (recommended): svn co http://josm.openstreetmap.de/svn/trunk
  • From the unofficial ​GitHub mirror: git clone git://github.com/openstreetmap/josm.git
  • From the official OSM Subversion repository (including plugins): svn co http://svn.openstreetmap.org/applications/editors/josm josm

Ubuntu repository

The repository for Ubuntu contains two packages:

josm

The tested version
Replaces the package from the official Ubuntu repository.

josm-latest

The development version (nightly build)
Can be installed parallel to the josm package. The default preference folder is ~/.josm-latest.

Installation

Depending on your Ubuntu-Version, add one of the following lines to your /etc/apt/sources.list:

deb http://josm.openstreetmap.de/apt lucid universe
deb http://josm.openstreetmap.de/apt natty universe
deb http://josm.openstreetmap.de/apt oneiric universe

Download and register the public key:

wget -q http://josm.openstreetmap.de/josm-apt.key -O- | sudo apt-key add -

Now refresh your sources

sudo apt-get update

and install:

josm

(You can skip the first line if you haven't installed these packages before.)

sudo apt-get remove josm josm-plugins
sudo apt-get install josm

josm-latest

sudo apt-get install josm-latest