Introduce The Mach Project

Project Mach was an operating systems research project of the Carnegie Mellon UniversitySchool of Computer Science from 1985 to 1994.

Work on the Mach operating system was started in 1985. Over the years the goals of the project have included:

• Providing interprocess communication fuctionality at the kernel level and using it as a building block for the rest of the system.
• Virtual memory support provided by the kernel and by user level servers.
• Kernel level support for light-weight threads.
• Support for closely and loosely coupled multi-processors and a variety of different commercially available workstations.
• Micro-kernel architecture limiting the functions supported by the micro-kernel and enabling multiple user level servers to support various Application and Programming Interfaces
• Maintaining at least one Unix-style API to enable the Mach system to support all the everyday uses of the project members and other researchers.
• Distributing this technology to other researchers and commercial sites to use as the basis for further research or products.

At this time the project has mostly come to a close at CMU. Parts of the Mach Operating system have been incorported in an number of commercial operating systems including:

• Encore's Multimax
• NeXT OS
• MachTen for the Macintoshes
• Omron's Luna
• DEC's OSF/1 for the DEC Alpha
• IBM's OS/2 for the RS6000 based machines.

Further research and development on Mach is being done by the Open Software Foundation.

The project at Carnegie Mellon ran from 1985 to 1994, ending with Mach 3.0. A number of other efforts have continued Mach research, including the University of Utah's Mach 4. Mach was developed as a replacement for the kernel in the BSD version of UNIX, so no new operating system would have to be designed around it. Today further experimental research on Mach appears ended, although Mach and its derivatives are in use in a number of commercial operating systems, such as NEXTSTEP and OPENSTEP, and most notably Mac OS X (using theXNU kernel). The Mach virtual memory management system was also adopted by the BSD developers at CSRG, and appears in modern BSD-derived UNIX systems, such as FreeBSD. Neither Mac OS X nor FreeBSD maintain the microkernel structure pioneered in Mach, although Mac OS X continues to offer microkernel Inter-Process Communication and control primitives for use directly by applications.

Mach is the logical successor to Carnegie Mellon's Accent kernel. The lead developer on the Mach project, Richard Rashid, has been working at Microsoft since 1991 in various top-level positions revolving around the Microsoft Research division. Another of the original Mach developers, Avie Tevanian, was formerly head of software at NeXT, then Chief Software Technology Officer atApple Computer until March 2006.