PowerPC Reference Platform (PReP) was a standard system architecture for PowerPC

PowerPC

PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...

 based computer systems (as well as a reference implementation

Reference implementation

In the software development process, a reference implementation is the standard from which all other implementations, with their attendant customizations, are measured, and to which all improvements are added...

) developed at the same time as the PowerPC processor architecture. Published by IBM

IBM

International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

 in 1994, it allowed hardware vendors to build a machine that could run various operating systems, including Windows NT

Windows NT

Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was intended to complement...

, OS/2

OS/2

OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "Personal System/2 " line of second-generation personal...

, Solaris, Taligent

Taligent

Taligent was the name of an object-oriented operating system and the company dedicated to producing it...

 and AIX

AIX operating system

AIX AIX AIX (Advanced Interactive eXecutive, pronounced "a i ex" is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms...

.

One of the stated goals of the PReP specification was to leverage standard PC hardware, and thus PReP was essentially a PC clone with a PowerPC CPU. Apple

Apple Computer

Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...

, wishing to seamlessly transition its Macintosh computers to PowerPC, found this to be particularly problematic. As it appeared no one was particularly happy with PReP, a new standard, the Common Hardware Reference Platform

Common Hardware Reference Platform

Common Hardware Reference Platform was a standard system architecture for PowerPC based computer systems published jointly by IBM and Apple in 1995. Like its predecessor PReP, it was conceptualized as a design to allow various operating systems to run on an industry standard hardware platform,...

 (CHRP), was developed and published in late 1995, incorporating the elements of both PReP and the Power Macintosh

Power Macintosh

Power Macintosh, later Power Mac, was a line of Apple Macintosh workstation-class personal computers based on various models of PowerPC microprocessors that were developed, marketed, and supported by Apple Inc. from March 1994 until August 2006. The first models were the Power Macintosh 6100,...

 architecture. Key to CHRP was the requirement for Open Firmware

Open Firmware

Open Firmware, or OpenBoot in Sun Microsystems parlance, is a standard defining the interfaces of a computer firmware system, formerly endorsed by the Institute of Electrical and Electronics Engineers . It originated at Sun, and has been used by Sun, Apple, IBM, and most other non-x86 PCI chipset...

 (also required in PReP-compliant systems delivered after June 1, 1995), which gave vendors greatly improved support during the boot process, allowing the hardware to be far more varied.

PReP systems were never popular. Finding current, readily available operating systems for old PReP hardware can be difficult. Debian

Debian

Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...

 and NetBSD

NetBSD

NetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...

 still maintain their respective ports to this architecture, although developer and user activity is extremely low.

Power.org has a new Power Architecture Platform Reference

Power Architecture Platform Reference

Power Architecture Platform Reference is an initiative from Power.org to make a new open computing platform based on Power Architecture technology. It follows two previous attempts made in the 1990s, PReP and CHRP....

 (PAPR) that provides the foundation for development of Power Architecture

Power Architecture

Power Architecture is a broad term to describe similar RISC instruction sets for microprocessors developed and manufactured by such companies as IBM, Freescale, AMCC, Tundra and P.A. Semi...

 computers based on the Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

operating system. The PAPR spec was in the fourth quarter of 2006.