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.

TwoCaptcha allows you to solve captchas with manual labor

DeathByCaptcha allows you to solve captchas with manual labor

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

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

Anti Captcha is an automated CAPTCHA solving service

This version include two important page 'Contact' and 'Register' with the 'Math-Captcha' method submit for prevent hacker attack.

Drop in feedback engine with customizable fields, and captcha available

0-9 arası sayıları kullanarak random olarak 2 sayı seçer ve yine random olarak toplama ya da çarpma yaparak sonucu verir.

This is a Captcha gem for ruby. 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

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

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

Gem that uses RuCaptcha API to solver any type of captcha