Part Seven

Case Studies

In the final part of the book, we integrate the concepts described earlier by examining real operating systems. We cover two such systems in detail—Linux and Windows 7. We chose Linux for several reasons: it is popular, it is freely available, and it represents a full-featured UNIX system. This gives a student of operating systems an opportunity to read—and modify—real operating-system source code.

We also cover Windows 7 in detail. This recent operating system from Microsoft is gaining popularity not only in the standalone-machine market but also in the workgroup–server market. We chose Windows 7 because it provides an opportunity to study a modern operating system that has a design and implementation drastically different from those of UNIX.

In addition, we briefly discuss other highly influential operating systems. Finally, we provide on-line coverage of two more systems: FreeBSD and Mach. The FreeBSD system is another UNIX system. However, whereas Linux combines features from several UNIX systems, FreeBSD is based on the BSD model. FreeBSD source code, like Linux source code, is freely available. Mach is amodern operating system that provides compatibility with BSD UNIX.