diffdmp

compare two text files (typically two versions of a text) using the diff-match-patch library, with semantic cleanup. produce an ordered list of additions, removals and identical text sections which allows for clear presentation of the differences, as well as recreating each of the texts.

launch from command prompt without any arguments for usage instructions.
library reference: https://github.com/google/diff-match-patch

this utility has a simple GUI wrapper:
http://vsspdiff.sf.net