These are the basic troff preprocessors shipped with DWB:

    - pic allows you to draw arbitrary line-drawing graphics in a
      machine-independent fashion.
    - eqn allows you to construct mathmatical equations.
    - tbl provides a mechanism for specifying and displaying
      automatically sized/configured tables 
    - grap uses pic to construct graphs.
    - refer provides a mechanism for searching for and formatting
      bibligraphic references.

Neither pic nor grap are included with CAT troff, but eqn, tbl and
frequently refer are present.  Groff does not at present support grap.

Some parts © 2009 Advameg, Inc.