Dan Cross writes:

> This is interesting; I've always felt like I could pick out troff pretty
> readily; I agree that TeX has a certain "look" to it (at least by default),
> but I always felt the same about troff as well.

My guess this is more about how ms(7) does page layout.  I can spot
those documents from a mile away :-)

But older versions of troff can often be spotted by how box corners
don't always line up properly.

A lot of people get turned off by how troff markup can often look
like line noise.  That's true, but if you spend the time to actually
learn the syntax (and it's really not that hard), you can't help
but be overwhelmed by the beauty of its self-consistency.  Although
after three decades I still can't wrap my head around traps and
diversions :-P

--lyndon