Diff tool for html documents, disregarding markup
jQuery: converting text into plain text including HTML Entities
Diff Match Path: http://code.google.com/p/google-diff-match-patch/
Underscore.js: Utility functions
to produce a html diff marking insertions and deletions using the
see the code of this method to get the individual steps if you want the diff in array form.
This library is released under the MIT license