Apple took an early lead in providing 64-bit support for desktop computers with Mac OS X Panther and the PowerMac G5 in 2003, which enabled users to tap into the G5's 64-bit instruction set. At that time, Intel's 64-bit strategy was Itanium IA64, but every year the outlook for the IA64 architecture got worse. Microsoft released an IA64 version of Windows XP, but nobody was buying any Itanium workstations so it didn't really matter. In 2002, HP bragged a distant lead in selling Itanium workstations (without stating exactly how many), but by 2004 it had dumped the entire line.
Alongside the new G5, AMD introduced the first processors using its new AMD64 architecture: the server-oriented Opteron in April 2003 and the desktop Athlon 64 in September. AMD64 enhanced the existing x86 family of CPUs with 64-bit instructions and other improvements rather than trying to replace it outright, as Intel had with the Itanium IA64. The industry had already aligned behind Itanium at great expense, so AMD's technology looked unlikely to make any headway in the PC world. In late 2000 a pundit in Windows IT Pro wrote, "Seeing Microsoft adopt the AMD chip is about as likely as seeing pigs fly."