WordPress.org

Requirements

• You need a free BotProof account here
• Your users will currently need to have Javascript enabled in their web browsers to see and complete the BotProof Captcha form. We will be releasing a version soon that supports browsers with Javascript disabled.
• Your theme must have a do_action('comment_form', $post->ID); call right before the end of your form (Right before the closing form tag). Most themes do.