Wrapper for Captchabot.com

generate captcha by dalli,use the memcache

Antigate (Decode captcha service) wrapper for Ruby

It's a Rails Captcha Engine for Rails 3 applications.

simple stupid captcha

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

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

Anti-spam protection for your website

A gem to generate captcha pictures.

Captcha-Plugin for Rails

A simple way to add zero friction captchas to Rails forms

Ruby wrapper for Yandex.Cleanweb

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

adds audio support to simple captcha

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

SimpleCaptcha is available to be used with Rails 3 + 4 or above and also it provides the backward compatibility with previous versions of Rails.

MVC based Math, Logic Captcha

This is mt first gem

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...

This library can help you create a captcha in your terminal application, which may be damaged by a large influx of requests.