Captchas and anti-spam Gems

#Total RankDaily RankNameSummary
1798790recaptchaHelpers for the reCAPTCHA API
22,1191,478invisible_captchaUnobtrusive, flexible and simple spam protection for Rails applications using honeypot ...
32,4171,991voight_kampffVoight-Kampff detects bots, spiders, crawlers and replicants
43,3573,964rakismetRakismet is the easiest way to integrate Akismet or TypePad's AntiSpam into your Rails ...