Pls Help-Looking for PHP Product for Articles

Hi, I'm looking for a product that will help me create a documentation system. I'd like to be able to post individual articles on an intranet, and have user's create comments on the articles that become part of the article. And editor could then review the comments and add to the article where appropriate, remove comments where appropriate. A good example of what I'm looking for is the kind of format used on this page: http://www.php.net/manual/en/ref.dbx.php where there's an article, and comments below it. Any ideas? Thanks, Steve