Anti-spam protection for your website

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

Russian Post tracking toolset, consisting tracking form bot (since Russian Post is too retarded for normal API) and captcha solver/recognizer.

Quick little arithmetic plain-text captcha

IQ, Math Captcha

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

dongsx

Simple negative captcha for Rails

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

Generates and verifies ascii art captcha.

Antigate (Decode captcha service) wrapper for Ruby

Description of TinyCaptcha.

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

A gem to generate captcha pictures.

Implementation of captcha (Completely Automated Public Turing-Test to Tell Computers and Humans Apart) that is both easy to use and easy to customize/extend.

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

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

Simple negative captcha for Rails

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

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