Later Brian's work was updated after V7 and
included some new tools, and became known as Writer's Workbench, which eventually was
entered in the 'toolchest.'
WWB wouldn't exist if text had not routinely existed in
machine-readable form, thanks to word-processing. But the impetus for
WWB came from "style", not from troff.
Style was a spinoff of Lorinda Cherry's "parts", which assigned parts
of speech to the words of a document. Style provided a statistical
profile of the text: measures such as average word length: frequency
of passives, adjectives and compound sentences, reading level, etc.
WWB in turn offered writing advice based on such profiles.
Style was stimulated by Bill Vesterman, a professor of English at
Rutgers, who brought the idea to me. I introduced him to Lorinda, who
had it running in a couple of weeks. Then Nina McDonald at USG
conceived and packaged WWB as a distinct product, not just a
collection of entries in man 1.
Wikipedia reports a surmise that WWB sank out of sight because it was
not a standard part of Unix distributions.
Doug