Captchas and anti-spam Gems

#Total RankDaily RankNameSummary
1765738recaptchaHelpers for the reCAPTCHA API
21,550910invisible_captchaUnobtrusive, flexible and simple spam protection for Rails applications using honeypot ...
32,2321,879voight_kampffVoight-Kampff detects bots, spiders, crawlers and replicants
43,5813,171rakismetRakismet is the easiest way to integrate Akismet or TypePad's AntiSpam into your Rails ...