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

Merb plugin that provides resource access rate limits and captcha'ing

Integrate the AreYouAHuman.com CAPTCHA alternative human verification into your Ruby/Rails application

Google reCaptcha helpers and verifier

This gem provides integration with TrustCaptcha for Ruby applications, offering CAPTCHA verification with a focus on security and privacy.

Metabypass | Ruby-based easy implementation for solving any type of captcha by Metabypass

Form protection with simple captcha calculations.

Solve Media CAPTCHA Replacement

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

Merb plugin that provides resource access rate limits and captcha'ing

Generates Text Catpchas, that are 'nice' by my own personal definition!

This plugin adds helpers for the YinXiangMa CAPTCHA API

A captcha that uses images instead of garbled text

AntiCaptcha api ruby wrapper

Captcha generator for rails

Description of RailsCaptcha.

Simple captcha

IQ, Math Captcha

Helper for Turnstile Captcha API

Easy to use classical captcha for Rails apps