A Rails captcha gem that attempts to determine whether or not a user is human.

ActsAsTextcaptcha provides spam protection for Rails models with text-based logic question captchas. Questions are fetched from Rob Tuley's textcaptcha.com They can be solved easily by humans but are tough for robots to crack.

This is a Captcha gem for Rails Applications. It drawing captcha image with C code so it no dependencies.

SimpleCaptcha is available to be used with Rails 3 + 4 or above and also it provides the backward compatibility with previous versions of Rails.

Captcha Client for YunPian.com

Unobtrusive, flexible and simple spam protection for Rails applications using honeypot strategy for better user experience.

Anti Captcha is an automated CAPTCHA solving service

TwoCaptcha allows you to solve captchas with manual labor

A gem to generate captcha pictures.

Easy to use classical captcha for Rails apps

这是一个验证码生成器。基于rucaptcha。本人只是将他的源码拉下来。为我的网站进行适配。因为我不使用sesion.id

A simple way to add honeypot captchas to Rails forms

Google reCaptcha helpers and verifier

Drop in feedback engine with customizable fields, and captcha available

This is a gem wrapper for tiny captcha in C with no dependencies.

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Gem that uses RuCaptcha API to solver any type of captcha

DeathByCaptcha allows you to solve captchas with manual labor

Captcha library which uses imagemagick to create captchas

Unity Captcha is a gem that use two levels of Captcha. First level is about Left Hemisphere: Logic and Math. Second level is about Right Hemisphere: Intuition and Drawing. This two levels functioning in complete harmony creates unity and this is the base design of this Captcha.