Chapter 1. History and Standards

Linux is a member of the UNIX family of operating systems. In computing terms, UNIX has a long history. The first part of this chapter provides a brief outline of that history. We begin with a description of the origins of the UNIX system and the C programming language, and then consider the two key currents that led to the Linux system as it exists today: the GNU project and the development of the Linux kernel.

One of the notable features of the UNIX system is that its development was not controlled by a single vendor or organization. Rather, many groups, both commercial and noncommercial, contributed to its evolution. This history resulted in many innovative features being added to UNIX, but also had the negative consequence that UNIX implementations diverged over time, so that writing applications that worked on all UNIX implementations became increasingly difficult. This led to a drive for standardization of UNIX implementations, which we discuss in the second part of this chapter.