83-640 is part of the Microsoft Certified Technology Specialist (MCTS) track, an alternative to taking 70-640.
This Technology Specialist (TS) exam, Exam 83-640: TS: Windows Server 2008 Active Directory, Configuring, became available in November 2008. This exam maps to the same objectives as 70-640, but this version (where available) contains a Performance Based component in addition to the standard exam item types. This exam is available in English only.