Intel Architecture 64-Bit, also termed IA-64, and was created in a joint venture between Intel and Hewlett Packard. Its goal was to create a Post-RISC architecture, ustilising a VLIW, or Very Long Instruction Word Architecture.
It bears almost no relation to the IA-32 Architecture, although it does possess an IA-32 Compatibility Mode, for execution of 32-Bit code, albeit at a 10x speed penalty.