Dries Buytaert,
Drupal's project leader, has just unveiled his latest Drupal project...
Mollom. Mollom's goal is to be an automated content monitoring system with one of its initial services geared toward providing a spam filter and CAPTCHA server for websites.
Dries Buytaert: Mollom, my content monitoring startup -
After several months of private beta testing, Benjamin Schrauwen and I are happy to unveil
Mollom, your partner in automated content monitoring. Mollom's purpose is to dramatically reduce the effort of keeping your websites clean and the quality of their user-generated content high. Currently, Mollom is a spam-killing, one-two punch combination of a state-of-the-art spam filter and CAPTCHA server. We are experimenting with automated content quality assessments, but these are still in an early testing phase.