On many sites communities begin with comments. And the comment features found in Drupal are deep enough that they can help you turn a website into a community.

Drupal not only contains many comment related features but also settings for each content type contained within your Drupal install. So you can have different comment settings for blog posts and pages for example. The screenshots below show the standard comment settings for Drupal.

Comment Settings

The standard comment settings contain many options to help you customize the experience for your users. You dcomments can be  threaded discussions or flat. When comments are flat each comment always appears after the previous one. Threaded discussion allow users to reply to specific comments and those replies are grouped together.

As of Drupal 6 comments are searchable. So when users search your site the returned results may include information contained in the comments. You can also provide a field that allows people to enter a title for their comment, which makes the comments have the feel of a forum. If you allow anonymous comments you can also choose to require that commenters provide contact information.

Protecting Comments

The access controls within Drupal give you the option to only make comments available to those who have registered for an account on your site. This feature provides you a certain amount of protection against malicious comments. Limiting comments to registered users can reduce the amount of comments you receive. You also have the option of editing the overall permissions for commenters so that all posted comments (or only those posted by anonymous users) will be held for approval. An example of the comment management queue is shown in the picture at left.

You can allow anonymous comments and still be protected if you add comment protection modules like Akismet or Mollom. Both of these modules call back to a central server to prevent comments that they think might be spam. I've tried both and they work well and can help keep your site protected.

A simpler option for protecting comments involves presenting a visual riddle to ensure that the poster is a human and not a machine.The captcha and recaptcha modules will add such a riddle at the end of your comment submission forms. Users must type in the correct word presented in order to successfully submit their comment. It's worth noting that captchas are not fool proof and some users get annoyed when presented with a captcha.

Extending Comment Functions

Drupal has plenty of modules that can help you add features to make comments more compelling. Comment RSS provides an RSS feed of comments for your site and for individual nodes. Comment Closer lets you shut down the comments on a particular node after a given amount of time. Comment Notify allows users to be notified automatically via email of follow up comments on a node.Comment Subscribe offers similar features to Comment Notify but allows you to only subscribe to direct replies of a particular comment.

A relatively new service called Disqus offers the ability to totally replace the Drupal comment system with a comment system manage on their servers. The Disqus module allows site owners to make that switch. Spam protection is then handled by Disqus but you also lose the ability of Drupal 6 to index the comments so that they may appear in your search results.

Tools For Site Administrators

There are a few different tools that can help a site adminstrator to stay on top of comments. By subscribing to the previously mentioned Comment RSS module you can stay abreast of recent site comments in your RSS feed reader. You could also use the comment RSS feed to create a widget (using a site like Widgetbox) that can be posted on another site or social network.

In Drupal 6 You can set up triggers and actions to generate an email each time a comment is posted on your site. The Subscriptions module appears to provide similar functionality. The Watcher module (currently only Drupal 5) allows node authors to receive notificatons of new comments via email.

Administrators also have to option of placing a recent comments block on their site. The recent comments block is a standard option in the block administration view for a Drupal install. When activated, the block will display a link to the ten most recently posted comments on your site in reverse chronological order.