Windows	12.7 Mb
Free.fr (France)
Cnet (World mirrors)
Automatic installer. Includes Java 1.3.1 (optimized for image processing).
Installation guide
Linux	45.5 Mb
Free.fr (France)
Automatic installer. Runs on any distribution. Its large size is due to Java 6 being bundled (optimized for image processing on Linux).
Installation guide
Mac OS X	2.6 Mb
Free.fr (France)
Disk image. Both compatible with Power PC and Intel Macs.
Installation guide
Debian, Ubuntu	3 Mb
Free.fr (France)
Debian package. Depends on Sun's JRE 6 (not compatible with openJDK)
Installation guide
Mandriva Linux 2010	2.9 Mb
Free.fr (France)
RPM package. Automatic installation works only on Mandriva, for it requires Sun's Java 6, which is not available anymore on main repository of other Linux distros
Installation guide

If you encounter any problem during download or installation, let me know.