Aard Dictionary

for Ubuntu
Aard Dictionary for Ubuntu 9.10 and newer

for Mac OS X
Aard Dictionary for Mac OS X 10.5 and newer (Intel)

for Windows
Aard Dictionary for Windows XP, Windows Vista, Windows 7

Source
Aard Dictionary source code

for Maemo 5
Aard Dictionary for Nokia Internet Tablets (N800/N810/N900)

Maemo 4.1 (N8x0) users can use Maemo 5 single click install, but must enable Diablo Extras-devel repository* first.

* Warning: Extras-devel is an unstable repository for testing unstable community software. It is recommended only for developers and adventurous users willing to test potentially harmful software.