• The Official CAPTCHA Site

    captcha.net CAPTCHA: Telling Humans and Computers Apart Automatically. A CAPTCHA is a program that protects websites against bots by generating and grading tests that humans can ...
  • No CAPTCHA reCAPTCHA - Google

    www.google.com/recaptcha/intro/index.html What is reCAPTCHA? reCAPTCHA is a free service that protects your website from spam and abuse. reCAPTCHA uses an advanced risk analysis engine and adaptive CAPTCHAs ...
  • CAPTCHA - Wikipedia, the free encyclopedia

    en.wikipedia.org/wiki/CAPTCHA A CAPTCHA (an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart") is a type of challenge-response test used in computing to ...
    • CAPTCHA | Drupal.org

      www.drupal.org/project/captcha A CAPTCHA is a challenge-response test most often placed within web forms to determine whether the user is human. The purpose of CAPTCHA is to block form submissions ...
    • CAPTCHA | Define CAPTCHA at Dictionary.com

      dictionary.reference.com/browse/captcha Called "CAPTCHA," it's essentially a test that's easy for a human to complete, but difficult or impossible for a computer to do.
    • Captcha by BestWebSoft — WordPress Plugins

      wordpress.org/plugins/captcha The Captcha plugin adds a captcha form into web pages. This captcha can be used for login, registration, password recovery, comments forms. It protects your website ...