wdiff (display word differences between text files)

The GNU wdiff program is a front end to diff for comparing files on
a word per word basis. A word is anything between whitespace. This is
useful for comparing two texts in which a few words have been changed
and for which paragraphs have been refilled. It works by creating two
temporary files, one word per line, and then executes diff on these
files. It collects the diff output and uses it to produce a nicer
display of word differences between the original files.