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.

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

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

DeathByCaptcha allows you to solve captchas with manual labor

Rails extension for Cloudflare's Turnstile CAPTCHA alternative. This gem should work with Rails 6.x, 7.x, 8.x and with Faraday 1.x and 2.x.

BrainBuster - a logic captcha for Rails

Rack middleware Captcha verification using Recaptcha API.

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.

Despamilator is a plugin based spam detector designed for use on your web forms borne out of two annoyances: Spam being submitted in my web forms and CAPTCHAS being intrusive. Despamilator will apply some commonly used heuristics from the world of anti-spam to help you decide whether your users a...

Drop in feedback engine with customizable fields, and captcha available

RubyGem package for visualCaptcha's backend service

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Arithmetic Captcha

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

FerrumMCP is a browser automation server that implements the Model Context Protocol (MCP), enabling AI assistants to interact with web pages through a standardized interface. Features include navigation, form interaction, content extraction, screenshot capture, JavaScript execution, cookie manage...

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

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

This version include two important page 'Contact' and 'Register' with the 'Math-Captcha' method submit for prevent hacker attack.

Generates Text Catpchas, that are 'nice' by my own personal definition!