BotDetect CAPTCHA is a website security CAPTCHA solution designed to prevent automated form submissions. It system is available for ASP, ASP.NET and PHP.

Features of BotDetect CAPTCHA:
- Time unlimited and fully functional free version;
- 60 secure & readable Captcha image styles;
- 10 secure & accessible Captcha sound styles;
- Localized Captcha generation, using various Unicode character sets and multi-language sound pronunciations;
- Custom Captcha image size, format, color scheme;
- Custom Captcha code length, style, character set, timeouts, generated code filtering;
- Produces XHTML 1.1 Strict and WCAG AAA compliant markup;
- Not dependent on other software so it does not bring in any additional dependencies;
- Includes high-quality samples;

What's New in This Version:
- Reorganized internal Captcha library dependencies to allow including the Captcha library in multiple websites from a central location
- Separated private and public library resources to allow independent deployment and security settings
- The BotDetect layout stylesheet is no longer automatically included by the BotDetect.php file, to allow more complex integration scenarios (multiple websites, various PHP frameworks etc.)
- Changed the format of the BotDetect/CaptchaConfig.php file to use a single global object for easier reuse and customization, implemented the CaptchaConfiguration helper for configuration settings access, added a new config section for Url settings
- Fixed a bug with Captcha code length randomization using the CaptchaRandomization helper; implemented the the Captcha randomization code sample
- Fixed a bug with the default BotDetect/CaptchaConfig.php configuration file not randomizing the Captcha image style
- Implemented BotDetect Captcha code filtering and the Captcha code filtering code sample
- Fixed a bug with the Captcha persistence code (taking into account that unserialize() returns false when loading fails; the code incorrectly checked for null)