Common Hardware Reference Platform

Common Hardware Reference Platform (CHRP) was a standardized set of specifications for PowerPC-based computer systems developed by the AIM alliance and published jointly by IBM and Apple Computer in 1995.

Description
Like its predecessor PowerPC Reference Platform (PReP), CHRP was conceptualized as a design to allow various operating systems to run on an industry standard hardware platform, and specified the use of Open Firmware and (RTAS) for machine abstraction purposes. Unlike PReP, CHRP incorporated elements of the Power Macintosh architecture and was intended to support the classic Mac OS and, in addition to the four operating systems that had been ported to PReP at the time (Windows NT, , , and AIX).

However, CHRP did not receive industry-wide adoption. The only CHRP-based systems to ship in appreciable numbers were servers from IBM's series running AIX. In 1997, Motorola had announced a CHRP-based Macintosh clone with a G3 processor, though it never reached the market. Mac OS 8 contains support for CHRP. Power Macintosh computers introduced in 1998 with New World ROMs, such as the iMac and blue & white Power Macintosh G3, utilized CHRP specs.

Successor
At the 2005 Worldwide Developers Conference, Apple CEO Steve Jobs announced that the company would switch to Intel processors, effectively abandoning PowerPC for future Macs. In the fourth quarter of 2006, published specifications for a newer  (PAPR) to provide a foundation for the development of -based computers running the Linux operating system.