Seems that Linux (and probably Mac OS X) versions can't switch interface language to Russian, though this translation works in Windows. Maybe some other languages are affected too. Or maybe this is some issue with the fonts in those operating systems.
It seems that this is a trivial "bug". Attaching Maxim's screenshot from http://www.igniterealtime.org/community/message/187218#187218
Some locale properties files has wrong names and doesnt appear in language selection because of that.