The primary target architectures of LFS are the AMD/Intel x86 (32-bit)and x86_64 (64-bit) CPUs.On the other hand, the instructions in this book are also known to work, with some modifications, with the Power PC and ARM CPUs. To build a system that utilizes one of these alternative CPUs, the main prerequisite, in addition to those on the next page, is an existing Linux system such as an earlier LFS installation, Ubuntu, Red Hat/Fedora, SuSE, or some other distribution that targets that architecture. (Note that a 32-bit distribution can be installed and used as a host system on a 64-bit AMD/Intel computer.)