Re: [TUHS] *roff history as told to GNU

I've been collecting a detailed narrative history not just of the *roff _programs_ but also of the development on the language in the roff(7) manual page.

The earliest known text-formatting software, TJ-2, was created by MIT-trained computer scientist Peter Samson in 1963. Its design and architecture set the stage for text-formatting and typesetting programs for the next several decades. […] TJ-2 read lines of text as its input. Each line was collected and formatted to make justified paragraphs (of monospaced type). However, if a line started with a special control code (“overbar,” in the lingo of the PDP-1 system, its host computer), the program interpreted it as a command. There were only a few commands, including a primitive line-centering mode, some simplistic indentation, and a command that left a specific amount of vertical space for a figure (e.g., illustration) to be inserted later. […] Note that TJ-2 did not interface with a phototypesetter — or any typesetter. Its output was destined to be printed on what was essentially an automatic typewriter outfitted only with monospaced fonts. While this seems a limitation, perhaps it was a necessary constraint at the time. But the TJ-2 went on to inspire (directly or indirectly) a long branch of typesetting software beginning with RUNOFF (“A Right-Justifying Type Out Program”) in 1964, a program that used “control words scattered in the text [to] provide detailed control over the format” of text. RUNOFF substituted TJ-2’s proprietary “overbar” control code with a simple period, and expanded the set of commands to produce line and page breaks and folios (page numbers). Then, in a fairly confusing list of technical begats over a decade or so, RUNOFF (capitals) led to “runoff” (lowercase), then to “rf,” “roff,” “nroff,” and “troff” — all software programs that utilized the same basic idea as TJ-2.