Comparison Tool For Article's & Feedback Window.

1)There should be one comparison Tool For Article's like when we post the article, whatever the editor make changes to the article, the two results should display like before(when we post the article) and after(the editor make changes) like the option we have for visual studio comparing changes with Server and local. 2)There should be feedback window so that editor can provide us with a feedback for our articles so that we can improve in our future articles.