In Chapter 7, Drupal, Spam, and Web Services, we looked in detail at using contributed modules that help to prevent and block spam submissions to your Drupal site. This included examples using the CAPTCHA and reCAPTCHA modules; the Antispam module; and a return to our earlier discussion in Chapter 1, About Drupal Web Services of using the Mollom spam service and module.
This module adds a CAPTCHA field to your Drupal forms including the contact form, user registration process, and your custom content types to help prevent spam submissions from machine-based visitors to your Drupal site.
Project page and URL: http://drupal.org/project/captcha
Maintainers: soxofaan, Rob Loach, wundo
Usage statistics: http://drupal.org/project/usage/captcha
Drupal modules page: http://drupalmodules.com/module/captcha
Current version: 6.x-2.2
The reCAPTCHA module extends the functionality of the CAPTCHA module by providing an integration of your Drupal site with the reCAPTCHA web service. To use this module, you'll need to sign up for an API key and account at the reCAPTCHA service application at: https://www.google.com/recaptcha/admin/create.
Project page and URL: http://drupal.org/project/recaptcha
Maintainers: Rob Loach, kthagen
Usage statistics: http://drupal.org/project/usage/recaptcha
Drupal modules page: http://drupal.org/project/usage/recaptcha
Current version: 6.x-1.4
The AntiSpam module allows for integration with multiple spam prevention web services including Akismet, TypePad, and Defensio. All three of these web service applications are accessible here:
Akismet: http://akismet.com
TypePad AntiSpam: http://antispam.typepad.com
Defensio: http://defensio.com
Project page and URL: http://drupal.org/project/antispam
Maintainers: pixture
Usage statistics: http://drupal.org/project/usage/antispam
Drupal modules page: http://drupalmodules.com/module/antispam
Current version: 6.x-1.2
We looked at the Mollom module and its project page and information in the Modules used in Chapter 1 section of this appendix.