Earlier quoted context omitted.
TeX (as a mostly batch formatter) didn't do this, but it did map ASCII quote characters to the typesetting ones. Including mapping a sequence of two single quote or backquote characters to the typeset double quotes. (FrameMaker was great, BTW. It was what got me into developing fancy layout style sheets and templates, which I later also did with Interleaf, MS Word, LaTeX, and various Web stuff. Somewhere in there, I…
Interestingly, the logic of mapping of two single quotes into a double quote was not built into TeX; rather, the metadata in each of the standard fonts simply used the ligature mechanism to handle it, just as they would specify that "f" followed by "t" should turn into the single-character "ft" ligature. It's a shame that ASCII (and its visual representation on terminals from most manufacturers) has a wonderfully sla…
See Markus Kahn's page at https://www.cl.cam.ac.uk/~mgk25/ucs/quotes.html which explains it well. (Also: the one-page documentation (plus one page implementation) of the LaTeX “upquote” package: http://mirrors.ctan.org/macros/latex/contrib/upquote/upquote... )