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

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.

Description of TinyCaptcha.

dongsx

A simple image captcha gem

IQ, Math Captcha

This is mt first gem

MVC based Math, Logic Captcha

create captcha for api based project

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

jQuery slide captcha system with jQuery & jQuery UI for Rails 3

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

Simple, easy captcha for Sinatra

Solve Media CAPTCHA Replacement

A very simple rack captcha middleware via captchator.com API

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

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

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

Helps humankind with simpler captchas