Confident Technologies provides free CAPTCHA security software called Confident CAPTCHA, a picture CAPTCHA that stops spam and ...

reCAPTCHA is a free CAPTCHA service that helps to digitize books, newspapers and old time radio shows. About 200 million CAPTC ...

Securimage is a script for generating complex images and CAPTCHA codes to protect forms from spam and abuse. It can be easily ...

visualCaptcha is a configurable captcha solution, focusing on accessibility & simplicity, whilst maintaining security. It' ...