Running 32-bit Applications on 64-bit Debian GNU/Linux
Advanced Micro Devices (AMD) developed a series of 64-bit extensions to their 32-bit RISC-based Intel IA-32 (i386) compatible processors. AMD sell their AMD64 (x86-64) architecture processors under a range of names: Athlon 64; Turion 64; Phenom; Opteron and Sempron (only the latest generation).
Initially Intel chose not to extend their IA-32 processor family to 64 bits, preferring to promote their own but incompatible HP PA-RISC based IA-64 "Itanium" processor family, later Intel adopted AMD's 64-bit extensions into their IA-32 processor family, calling them "Intel 64" (aka IA-32e and EMT64). Final generation Pentium 4 & D, Celeron D, and Xeon processors and all "Core 2" based processors now include AMD compatible 64-bit extensions.