A honeypot style captcha extension for ActiveRecord. Simple one-line inclusion in the model combined with a simple form field should trap the bad guys in the molasses.

wxianfeng_simple_captcha is captcha for rails,modified from simple_captcha .

Ruby wrapper for Yandex.Cleanweb

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

Use Turnstile by Cloudflare to perform captcha validation in your Rails app

Google reCaptcha helpers and verifier

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

Simple captcha

Define questions and answers in a YAML file and validate your models with a single line of code. No more captchas or other stupid tricks.

Ruby port of VIT AutoCaptcha

Display and verify arcaptcha service captcha

A simple and custom captcha for Rails3.

anti-captcha is a Ruby library for recognize captcha on anti-captcha.com

Implements view helpers for the ASIRRA CAPTCHA system for Rails-based websites

Submit captcha images and retrieve the text as a string.

Captchator as Rack middleware, and helpers for sinatra.

Generates and verifies ascii art captcha.

Simple negative captcha for Rails

API to interact with BrandCAPTCHA http://www.pontamedia.com/en/brandcaptcha/

generate captcha by dalli,use the memcache