First versions of Absolute Comments implemented several features that are now, out of the box, part of WordPress.
Absolute Comments now simply adds a “Reply” link into comment notification emails, prefills the comment reply with the commenter’s name, and adds a few cute icons.
There’s no option or settings: just activate and forget it’s even a plugin.
Official page: Absolute Comments
Tip: To keep track of this plugin’s evolution and features, you are advised to subscribe to the author’s feed or follow him on Twitter: @ozh