BuddyPress.org

I’ve mentioned this before but it went ignored, perhaps nobody was interested at the time? lol

I’m not sure how localization works with BuddyPress, but I’m guessing it just takes the WPLANG constant which can be defined in wp-config.php

There are language switching plugins out there which define this on a per-user basis, perhaps try getting the basic WPLANG definition feature from this ( http://www.poplarware.com/languageplugin.html ) working with WPMU/BuddyPress?