This excerpt taken from the ATVI 10-K filed Jun 14, 2007.
XBOX LIVE SERVER PLATFORM ADDENDUM
This Xbox Live Server Platform Addendum to the Xbox 360 Publisher Licensing Agreement (this XLSP Addendum) is entered into and effective as of the later of the two signature dates below (the Effective Date) by and between Microsoft Licensing, GP, a Nevada general partnership (Microsoft), and Activision Publishing, Inc. (Publisher), and supplements the Xbox 360 Publisher License Agreement between the parties dated as of 10/25/05 (the Xbox 360 PLA). Except as expressly provided otherwise in this XLSP Addendum, capitalized terms have the same meanings ascribed to them in the Xbox 360 PLA. The terms of the Xbox 360 PLA are incorporated by reference, and except to the extent expressly modified by this XLSP Addendum, the Xbox 360 PLA remains in full force and effect and is hereby ratified and confirmed.