Microsoft XCPU, codenamed Xenon, is a CPU used in the Xbox 360 game console, to be used with ATI's Xenos graphics chip.The processor was developed by Microsoft and IBM under the IBM chip program codenamed "Waternoose", which was named after Henry J. Waternoose III in Monsters, Inc.. The development program was originally announced on 2003-11-03.The processor is based on IBM PowerPC instruction set architecture. It consists of three independent processor cores on a single die.