This page describes ports of ReactOS to different architectures.
Intel x86 ("i386")
The family of Intel 8086-compatible instruction set architectures from the Intel 80386 onwards. Development of ReactOS is based fist and foremost on supporting this instruction set architecture.
Xbox is a gaming console developed by Microsoft. The Xbox port of ReactOS was intended for the original Xbox console, which Microsoft has discontinued since 2006. It ran on a custom Pentium III processor which ReactOS could support, though a new hardware abstraction layer needed to be written to be used. The port was started at r11926, but has since regressed and is unmaintained.
AMD64 refers to AMD's specifications for a 64-bit extension to the x86 instruction set. The ros-amd64-bringup branch was created on r34699 by Timo Kreuzer for porting ReactOS to this architecture. Most of the code is shared between amd64 and i386.
Main article: ARM Port
ARM is a 32-bit RISC architecture developed by ARM Holdings. The ReactOS port to the ARM architecture is maintained by the Portable Systems Group under the name ros-arm-bringup in the trunk directory.
PowerPC is a 32-bit/64-bit RISC architecture developed by the Apple-IBM-Motorola alliance. From r14755 to r29962 PowerPC had its own branch, while work prior to and after the branch have been committed to the trunk. The PowerPC port is developed by Art Yerkes. It was the first try to port ReactOS to another architecture, as result there was a lot of stuff, that prepared ReactOS for other ports.