We are looking to implement a rich-text box in an ASP.NET application and our requirements are specific to using the "Track Changes" features of Microsoft Word. The closest thing we found in the RadEditor by Telerik. This is a nice control that has a "Track Changes" button and will give you the ability to track the changes from the text in the box to now. It does not let you track your changes from the two previous versions.

We have used CVSWeb in the past and the display was not great but it did have the ability (in a web page) to diff two different versions of text (source code in this case).

Does anyone have any experience or know of any web-based diff tools that work nicely with a rich-text editor in the web?