"The POWER architecture describes a family of RISC CPUs that
arose out of a consortium of IBM, Apple, and Motorola. Within this
chip family, higher-end POWER4 chips are used in various IBM
mid-range machines; at a personal computer, workstation, or
workgroup-server level, the PowerPC branch of POWER chips are used
in widely-used consumer machines from Apple Computer. Chips in the
PowerPC family--especially those from Motorola--are also used in
various embedded and specialized systems, including PCs from
smaller manufacturers such as the phoenix-like current incarnation
of Amiga.
"The interrelations among various POWER architecture chips are
similar to those in the x86 world--for the most part, later
generations of chips provide backward compatibility with earlier
ones while also offering new and enhanced capabilities. Within the
PowerPC family branch, five-year-old Apple machines used 601, 603,
and 604 model chips. The current models have phased out the G3 but
continue to use the similar G4, both 32-bit chips, running at
various clock speeds; the recently introduced G5 is a 64-bit IBM
chip that mostly adds some multimedia-specialized instructions to
the POWER4 chip models.
"The bottom line on all these chips, from a Linux developer's
perspective, is that they all run Linux happily and well. For the
PowerPC branch of the chips, excellent consumer-friendly
distributions are available and offer commercial customer support.
IBM also installs Linux for customers of its high-end POWER4
machines..."