I just published a web site that contains drafts of documents I'm working on. They'll be updated frequently, and I need an easy way to inform my readers of changes to the documents that concern them.

The obvious solution to this problem is RSS. I assume it's not too hard to support RSS in the Apache HTTP Server -- I haven't researched it yet -- but I think that's not what I need, or not all I need, because it isn't fine-grained enough. When I change a document, my readers will want to know what changed. Did I rework the whole thing, add a particular topic that may or may not interest them, or fix a typo? Is there an automated way to deliver that type of information?