In this appendix we examine the Mach operating system. Mach is designed
to incorporate the many recent innovations in operating-system research to
produce a fully functional, technically advanced system. Unlike UNIX, which
was developed without regard for multiprocessing, Mach incorporates multiprocessing
support throughout. Its multiprocessing support is also exceedingly
flexible, accommodating shared-memory systems as well as systems with no
memory shared between processors. Mach is designed to run on computer
systems ranging from one processor to thousands of processors. In addition,
Mach is easily ported to many varied computer architectures. A key goal of
Mach is to be a distributed system capable of functioning on heterogeneous
hardware.
