ZeroCaptcha allows companies to solve captchas with artificial intelligence software, which is faster than humans and very accurate

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

A very simple rack captcha middleware via captchator.com API

This gem enable to use Captchme. Anti spam, Monetize captcha and Audience qualification

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

My version of SimpleCaptcha

Ruby port of VIT AutoCaptcha

wxianfeng_simple_captcha is captcha for rails,modified from simple_captcha .

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

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

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

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 Captcha gem for Rails Applications. It drawing captcha image with C code so it no dependencies.

Captcha-Plugin for Rails

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

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

ReCaptcha implements view helpers to generate ReCaptcha code, with the noscript counterpart, required methods that interface with the HTTP API for captcha verification, a DSL to generate a before_filter and the code to implement AJAX captcha validation.

这是一个验证码生成器。基于rucaptcha。本人只是将他的源码拉下来。为我的网站进行适配。因为我不使用sesion.id

ActsAsTextcaptcha provides spam protection for Rails models with text-based logic question captchas. Questions are fetched from Rob Tuley's textcaptcha.com They can be solved easily by humans but are tough for robots to crack.

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