It is quite appropriate for us to consider and remember the roots of the UNIX operating system. While originally written to provide a comfortable environment for software development and operating system research, UNIX quickly became a staple for a variety of other purposes and used by a number of groups at AT&T Bell Labs and elsewhere.
Among the first uses of UNIX was the creation of documentation, and tools for writing documentation were created early in UNIX history. In fact, an early version of UNIX, called the Documenter's Workbench was assembled specifically for this purpose.
Another was the Programmer's Workbench, which was originally designed for a 1000 member programming team within AT&T.
Third was a Writer's Workbench that contained applications that writers find of value.
These systems formed the basis of modern UNIX and Linux systems, which still benefit from many of the innovations in the early systems.