We are happy to announce the release of yet another Drupal module. This time it is the "Comment Subscribe" module that will allow anonymous as well as registered users on a drupal site to subscribe to replies to their comments. The module will send notifications to the subscribed users about the replies to their comments or replies to their comment's children.
You can read more about the module and get yourself a copy of the module from
Comment Subscribe module home page on drupal.org
The module has also been ported for Drupal 6.x. You can read the announcement from
Announcement on drupal.org forums about porting of Comment Subscribe Module to Drupal 6.x
You can download any of the releases for Comment Subscribe from
List of Releases of Comment Subscribe module