A series of CPUs designed in cooperation between Motorola and IBM, based on the POWER architecture of IBM. IBM use PowerPC family processors in their mainframe systems and often design new features into their processors which eventually make the way down to the desktop processors which power new AppleMacintosh computers. (See G3 and G4.)
Linux has been ported to the PowerPC. See 
Debian, PenguinPPC and LinuxPPC
Quoting http://e-www.motorola.com/webapp/sps/site/homepage.jsp?nodeId=03M943030450467 : Motorola microprocessors are nothing short of revolutionary. From its inception, the scalable PowerPC architecture was designed to meet the highly diverse needs of solutions ranging from desktop computer CPUs to high-performance, highly integrated embedded MPUs. Compelling price/performance, extended temperature options, multiprocessing capabilities, high levels of integration, instruction set compatibility across the entire product line, and the broadest selection of development tools have led to rapid adoption across the industry. Today, solutions implementing the PowerPC architecture are chosen for more current and planned embedded designs than any other architecture.
The PowerPC architecture is an ideal foundation for RISC embedded applications; its minimal silicon requirements allow for higher integration, making it possible to pack a complete processor core and substantial peripheral functions on one chip, while simultaneously reducing power consumption and heat generation. Using this adaptable technology, Motorola delivers the latest high-performance RISC technology in integrated, single-chip products ideal for price-sensitive mainstream markets.
18 pages link to PowerPC:
