First officially released with Debian 4.0. Port to 64-bit x86 processors. The goal is to support both 32-bit and 64-bit userland on this architecture. This port supports AMD’s 64-bit Opteron, Athlon and Sempron processors, and Intel’s processors with Intel 64 support, including the Pentium D and various Xeon and Core series.
Version 8 of the ARM architecture included AArch64, a new 64-bit instruction set. Since Debian 8.0, the arm64 port has been included in Debian to support this new instruction set on processors such as the Applied Micro X-Gene, AMD Seattle and Cavium ThunderX.
A lot of modern 32-bit ARM boards and devices ship with a floating-point unit (FPU), but the Debian armel port doesn’t take much advantage of it. The armhf port was started to improve this situation and also take advantage of other features of newer ARM CPUs. The Debian armhf port requires at least an ARMv7 CPU with Thumb-2 and VFPv3-D16 floating point support.
The first architecture, and not strictly a port. Linux was originally developed for the Intel 386 processors, hence the short name. Debian supports all IA-32 processors, made by Intel (including all Pentium series and recent Core Duo machines in 32-bit mode), AMD (K6, all Athlon series, Athlon64 series in 32-bit mode), Cyrix and other manufacturers.
First officially released with Debian 3.0. Debian is being ported to the MIPS architecture which is used in SGI machines (debian-mips — big-endian) and Digital DECstations (debian-mipsel — little-endian).