IBM Workplace OS

Workplace OS was born in 1991 as an ambitious plan by IBM to create a new computer operating system. The goal of Workplace OS was to improve software portability and reduce maintenance costs of IBM's software by using a common microkernel base for all of IBM's operating systems.

At the base of Workplace OS was a version of the Mach 3.0 microkernel (release mk68) developed by Carnegie Mellon University and heavily modified by the Open Software Foundation's Research Institute. On top of the microkernel, Workplace OS was to run servers (also called "operating-system personalities") that would execute DOS, OS/2, Microsoft Windows, OS/400, and AIX applications. IBM had planned for Workplace OS to run on several processor architectures, including PowerPC, ARM, and x86 computers, and ranging in size from PDAs to workstations to large servers.

IBM saw the easy portability of the Mach-based Workplace OS as creating a simple migration path to move their existing x86 (DOS and OS/2) customer base onto PowerPC-based systems. IBM hedged their operating system strategy by aggressively trying to recruit other computer companies to adopt its microkernel as a basis for their own operating systems. In 1992, IBM persuaded Taligent to replace its own internally developed microkernel with the IBM microkernel. Ostensibly, this would have allowed Taligent's operating system (implemented as a Workplace OS personality) to execute side-by-side with DOS and OS/2 operating system personalities.

The initial internal-development versions of Workplace OS ran on x86-based hardware and provided a robust BSD Unix derived personality and a DOS personality.

The inherent difficulty of implementing a kernel with multiple personalities, and poor communication between the teams implementing the different personalities, are largely blamed for the failure and the two billion dollar cost. Throughout the project, poor performance was accepted on the belief that the high speed of PowerPC hardware would make it a non-issue. This turned out to be a false belief. Eventually, the PowerPC kernel with the OS/2 personality, and a new UNIX personality, was released as a commercial product in October 1995. In 1996, a second version was released that also supported x86 and ARM processors. Faced with poor performance; low acceptance of the PowerPC Reference Platform (on which the initial offering ran); poor quality of the PowerPC 620 platform; extensive cost overruns; lack of AIX, Windows, or OS/400 kernel personalities; and resulting low customer demand, the project was cancelled.

Upon cancellation, IBM closed both the Workplace OS project and the Power Personal Division responsible for low end PowerPC processors. The other long term effect was that IBM decided to stop developing new operating systems, and committed heavily to using Windows and Linux.