The Free On-line Dictionary of Computing (18 March 2015):
Apple Computer's personal computer based on the
PowerPC, introduced on 1994-03-14.
The Power Mac G4 (Quicksilver 2002) was the first Power Mac to
clock at 1 GHz. In mid-2003, the Power Mac G5 was released,
the first Mac to be based on a 64-bit architecture. IBM
manufactured the CPU for this new model. The clock speed was
initially 1.6 GHz but a dual 2 GHz system was available in
September. Existing 680x0 code (both applications and
device drivers) run on Power Mac systems without modification
via a Motorola 68LC040 emulator. The performance of these
unmodified applications is equivalent to a fast 68040-based
Macintosh, e.g. a fast Macintosh Quadra.
The Power Mac runs Macintosh operating system from System
7.5 to Mac OS 8.5.
Latest version, as of 2003-11-26: Power Mac G5.
Power Mac Home (http://apple.com/powermac/).