ReCaptcha implements view helpers to generate ReCaptcha code, with the noscript counterpart, required methods that interface with the HTTP API for captcha verification, a DSL to generate a before_filter and the code to implement AJAX captcha validation.

MVC based Math, Logic Captcha

RMagickCaptcha is a gem that implements captcha for using in Rails application.

Use Turnstile by Cloudflare to perform captcha validation in your Rails app

Simple gem to add captcha or negative captcha to your Rails 3 application

My version of SimpleCaptcha

A captcha that uses images instead of garbled text

Simple lib to generate a math_captcha to prevent spammers in form. Supports localization.

Solve Media CAPTCHA Replacement

Captcha Gem for Rails, which generates captcha image by Rust.

Rails mountable engine, that provides captcha support

A Google-style captcha for enterprise Rails apps

IQ, Math Captcha

Simple captcha

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

simple stupid captcha

Define questions and answers in a YAML file and validate your models with a single line of code. No more captchas or other stupid tricks.

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

Repackaged visualCaptcha's backend service, including translation and minor modification. Mainly for private use. Everything still belongs to original author: emotionLoop.

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