ZZEE Human Pictcha is a protection in a form of an image (a captcha), which can be embedded inside your web form, and which will filter out various forum spam, guestbook spam, form spam, signup spam, password attack, etc. It is a library and a set of tools and examples for PHP and can be used with Perl as well.Human Pictcha is fairly easy to install and embed into your existing PHP or Perl forms. You can download a free demo version to see if it is compatible with your web site and how easy to use it in your forms. Human Pictcha comes with the full open source, which is a big advantage.
For PHP or Perl forms
Easy to setup and maintain
Full open source
Compatible with the typical webserver setup
Secure and hard to defeat by OCR
You can tune it to match your website looks
Complete documentation
Image code can consist of digits and letters or only digit, making it easy to adapt to international markets
You can significantly adjust the level of protection by enabling or disabling security features and changing various parameters