IA-64 is the instruction set architecture (ISA) of the Itanium family of 64-bit Intel
microprocessors. The basic ISA specification originated at ... HP made a
substantial contribution to the ISA definition, the Merced/Itanium
microarchitecture, and Itanium 2, but productization responsibility was Intel's. The
original goal ... By the time Itanium was released in June 2001, its performance
was not superior to competing RISC and CISC processors. ... For AMD64 and
Intel64 architecture, see x86-64.