Simple Audio Extension to Simple Captcha

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

Death by Captcha Ruby implementation (HTTP API)

Captcha Client for YunPian.com

A simple image captcha gem

generate captcha by dalli,use the memcache

Rails mountable engine, that provides captcha support

adds audio support to simple captcha

A simple and custom captcha for Rails3.

A simple CAPTCHA implementation for Rails 5+ based on RMagick.

MVC based Math, Logic Captcha

Gem that uses RuCaptcha API to solver any type of captcha

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

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

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

This is a Captcha gem for ruby. It drawing captcha image with C code so it no dependencies.

RedisCaptcha provides simple captcha that can be read by human.

DeathByCaptcha allows you to solve captchas with manual labor

Rack middleware Captcha verification using Recaptcha API.

BrainBuster - a logic captcha for Rails