dwdiff is a front-end for the diff program that operates at the word level
instead of the line level. It is different from wdiff in that it allows the
user to specify what should be considered whitespace, and in that it takes an
optional list of characters that should be considered delimiters. Delimiters
are single characters that are treated as if they are words, even when there
is no whitespace separating them from preceding words or delimiters.