Re: [groff] anyone seen ".ny0" ?

[Ingo Schwarze]

Hi Tadziu,

Tadziu Hoffmann wrote on Mon, Mar 25, 2019 at 09:55:31PM +0100:
> Ingo Schwarze wrote:

>> I would say it is almost certain that it used to be some
>> X11-specific hack decades ago that has never been maintained
>> or tested since, because neither GNU troff nor Heirloom troff
>> define an .ny or .ny0 request.

> In the Xlib documentation, the ".ny0" first appeared in X11R1
> (apparently with no explanation), X10R4 did not yet have it.

Did .IN, by any chance, appear at the same time?
Not sure it's important, but if the two appeared together,
then they are likely both related to some home-grown indexing
system that has fallen into oblivion many years ago.

> And from looking at the source code, it appears that AT&T troff
> also never had an _undocumented_ .ny request (unless it was
> carefully hidden).
> 
> If it's not a typo that went unrecognized because it didn't do
> any harm, then perhaps the .ny0 was intended for some other
> troff (being simply ignored by AT&T troff)?  The Makefile
> runs "psroff", but I thought that was only a wrapper for the
> regular troff to generate Postscript output.  Were any other
> troffs in widespread use at the time (ca. 1985)?

I doubt it.  There have certainly been some niche implementations
at various times and some forks from the main lines, but i never
heard that any important forks diverged much, or that any independent
reimplementations were influential before the advent of GNU troff.

The three main lines seem to be

 1. AT&T / DWB / Kenighan "device independent" / Plan 9 troff
 2. Solaris / Heirloom troff (actually a SysV fork of line 1)
 3. GNU troff

Unless i'm quite mistaken, everything else is much younger.

If you are talking about ~1985, then even the lines 1 and 2 had
only forked quite recently, if at all: System V Release 1 happened
in January 1983, SunOS 1.0 later the same year, both based on Sytem
III and on 4.1BSD, which all used Kernighan's device independent
AT&T troff at the time; BSD switched over to GNU troff a few years
later.

Yours,
  Ingo