A RISC microprocessor chip designed in 1991 by a partnership between IBM, Apple, and Motorola. The processor has a 64-bit architecture. The initial 601 chip was followed by the 603 and 620 versions. From the 740 onwards, better performance and reliability was obtained by using copper (instead of aluminum) in the manufacturing process. The chip appeared in Apple's PowerMac systems until 2006 and is still used in IBM systems using the AIX operating system. It is also widely used in embedded systems.