David Golub, Randall Dean, Alessandro Forin, Richard Rashid. Unix as an Application Program. [postscript] This article appears in the Proceedings of the USENIX Summer Conference, June 1990.

This is an introduction to the Mach 3.0 kernel.

Since March 1989 we have been running at CMU a computing environment in which the functions of a traditional Unix system are cleanly divided into two parts:facilities which manages the hardware resources of a computer system(such as CPU. I/O and memory)and support for higher-level resource abstractions used in the building of application programs, e.g. files and sockets. This paper describes the implementation of Unix as a multithreaded application program running on the Mach kernel. The rationale, design, implementation history and performance of the system is present.