A library to make creating negative captchas less painful

A plugin to make the process of creating a negative captcha in Rails much less painful

reCAPTCHA was too much for us, so we created this. Simplest captcha ever.

Drop in feedback engine with customizable fields, and captcha available

Google reCaptcha helpers and verifier

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

TwoCaptcha allows you to solve captchas with manual labor

Unobtrusive, flexible and complete spam protection for Rails applications using honeypot strategy for better user experience.

DeathByCaptcha allows you to solve captchas with manual labor

adds audio support to simple captcha

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

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

Anti Captcha is an automated CAPTCHA solving service

A simple way to add honeypot captchas to Rails forms

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.

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.

Captcha-Plugin for Rails

BrainBuster - a logic captcha for Rails

Rack middleware Captcha verification using Recaptcha API.

RubyGem package for visualCaptcha's backend service