ALTCHA is a free, open-source CAPTCHA alternative that protects your website from spam and abuse

Simple reverse captcha solution that consist in create a hidden field that should be always empty.

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.

A gem to generate captcha pictures.

To help with keep the bots at bay this gem helps you easily add honeypots to forms and/or obfuscate your form field names

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

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

Description of RailsCaptcha.

RedisCaptcha provides simple captcha that can be read by human.

Death by Captcha Ruby implementation (HTTP API)

Gem that uses RuCaptcha API to solver any type of captcha

create captcha for api based project

MVC based Math, Logic Captcha

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

This is mt first gem

A simple image captcha gem

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

dongsx

HumanDetector is a friendly logic captcha for Rails the doesn't require any external system dependency (e.g. external captcha API connections). It uses a simple question that any 7 or more years old human can understand, but that a spambot will not be able to answer. This Gem supports Ruby v1.9.2...

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