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

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.

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

BrainBuster - a logic captcha for Rails