Itanium

The architecture was built on EPIC (Explicitly Parallel Instruction Computing), a VLIW variant in which the compiler — not the processor — was supposed to schedule parallel instructions. Intel and Hewlett-Packard began the partnership in the 1990s; the first chip, "Merced", shipped in 2001 and was meant to replace both x86 and HP's own PA-RISC.

It didn't work out that way. Compilers never managed to feed the wide instruction bundles the design demanded, performance disappointed, and x86 emulation was sluggish. When AMD instead extended x86 to 64 bits (AMD64, 2003), the market chose backward compatibility. Itanium survived longest in HPE's mainframe-class servers running OpenVMS and HP-UX; the last chip (Kittson) sold through 2021. Few architectures have ever been handed a more fitting nickname.