Movable Type 4 introduced a neat feature, a handy
Reply is now available to authors from the comment management screens. This allows authors to reply to comments from within the application and as a result also introduced some basic comment threading features. In fact, a series of template tags were created but there have been two large holes so far:
Commenters were left in the cold! The only way to reply to specific comments was from within the application, there is absolutely no way to reply to comments from the blog's entry archive.
There was no documentation - although the above tags were available, there was next to no documentation on how to use them or create comment threads.
Enter Simply Threaded, rewritten for Movable Type 4's comment threading, provides you with the template tags you need to allow commenters to reply to comments. Not only that but (as the sidebar shows), documentation guides you through the process of creating either traditional hierarchical threads or the newer styles of chronological threads.