''Software Tools'', by [Brian Kernighan] and P.J.Plauger, Addison-Wesley, 1976, is an older book which showed the reader step by step how to build a UNIX-like environment on any system that supported a decent Fortran compiler, including almost all the source you needed. By the time you finished all the exercises, you had [Ratfor], '''roff''', [m4], '''ed''', [grep], and other tools... the core of the UNIX command-line environment. The tools were portable, and implemented a virtual file system on top of a native file system that allowed the [Unix]-like system to run on everything from CP/M-80 to Cray systems. A few years later, ''Software Tools in Pascal'' was released, achieving the same goal for the next language to be popular. [RS] made his first steps in C with Jim E. Hendrix's "Small C", which contained a suite of tools modeled closely after Kernighan/Plaugher, on a Z80+ machine. I was most amazed by the simplicity that most tools read from stdin, wrote to stdout, so they could be easily coupled into pipes. ---- [Category Book]