Par is similar but superiour to the fmt(1) command included in the
    base system.

    Par is a filter that copies its input to its output, changing all
    white characters (except newlines) to spaces, and reformatting
    each paragraph.  Paragraphs are separated by protected, blank, and
    bodiless lines (see the Terminology section for definitions), and
    optionally delimited by indentation (see the d option in the Options
    section).

    Each output paragraph is generated from the corresponding input
    paragraph as follows:

     1) An optional prefix and/or suffix is removed from each input line.
     2) The remainder is divided into words (separated by spaces).
     3) The words are joined into lines to make an eye-pleasing paragraph.
     4) The prefixes and suffixes are reattached.

     If there are suffixes, spaces are inserted before them so that they
     all end in the same column.

WWW: http://www.cs.berkeley.edu/~amc/Par/