Recommend a diff tool to show and explain some changes in a document

Question

Now I'm in process of contract negotiation with a private company. They sending me the contract, I'm making some changes and then sending back to them for verification. Now they asking me to explain every change I done, but I can't remember them all. MSWord's diff tool is displaying too many useless changes, and I can't "ignore" some of them manually.

I guess I need something similar to KDiff tool, but with these extra features:

• the ability to comment some differences between 2 versions of a text file.
• the ability to ignore some non-significant differences (for example, changing hyphen into dash, or removing multiple spaces)
• the ability to create an HTML or PDF report with explanations about changes.

Can you recommend some tool for my task? (freeware is preferred)

Answer 1

SmartBear CodeCollaborator does that stuff, but it's not free. However, they've occasionally offered specials for a limited 5-user version of CodeReviewer for as little as $5.