It looks like Drupal's localization (l10n) and internationalization (i18n) features were used to translate the website into 3 languages; an Arabic translation is available as well. (Arabic is written predominantly right-to-left which, frankly, is funny to watch but hard to implement in a CMS.)
Roughly a week ago, Wim Mostrey from CivicActions already gave a sneak preview of the new Amnesty Interational site at Barcamp Brussels. One remarkable fact that I'd would like to learn more about is the integration with Alfresco, an Open Source document management system written in Java.
— Dries Buytaert