troff

troff: /T'rof/ or /trof/ n.   [UNIX] The gray
   eminence of UNIX text processing; a formatting and phototypesetting
   program, written originally in PDP-11 assembler and then in
   barely-structured early C by the late Joseph Ossanna, modeled after
   the earlier ROFF which was in turn modeled after Multics' RUNOFF by
   Jerome Saltzer (*that* name came from the expression "to run
   off a copy").  A companion program, {nroff}, formats output for
   terminals and line printers.

   In 1979, Brian Kernighan modified `troff' so that it could
   drive phototypesetters other than the Graphic Systems CAT.  His
   paper describing that work ("A Typesetter-independent troff,"
   AT&T CSTR #97) explains troff's durability.  After discussing the
   program's "obvious deficiencies -- a rebarbative input syntax,
   mysterious and undocumented properties in some areas, and a
   voracious appetite for computer resources" and noting the ugliness
   and extreme hairiness of the code and internals, Kernighan
   concludes:

     None of these remarks should be taken as denigrating Ossanna's
     accomplishment with TROFF.  It has proven a remarkably robust
     tool, taking unbelievable abuse from a variety of preprocessors
     and being forced into uses that were never conceived of in the
     original design, all with considerable grace under fire.

   The success of {{TeX}} and desktop publishing systems have
   reduced `troff''s relative importance, but this tribute
   perfectly captures the strengths that secured `troff' a place
   in hacker folklore; indeed, it could be taken more generally as an
   indication of those qualities of good programs that, in the long
   run, hackers most admire.