Extension freeCap CAPTCHA (extension key: sr_freecap) is a library that integrates into the TYPO3 framework the open source script freeCap v1.4.1 and allows to add a CAPTCHA image on a frontend form.

Citing the author of freeCap: «It can be used to prevent comment spam, guestbook spam, automated signups or any area of your website where you fear the evil spammers may target.»

The extension features optional audio output in order to produce an accessible CAPTCHA. This feature is based on initial ideas by Philip Almeida and wav files joining script by Andreas Gohr.

The extension also includes a backend module to create GD font files that are used to create the CAPTCHA images. This backend module is based on GD fontMaker v1 from the author of freeCap.

For more information on CAPTCHA, see http://en.wikipedia.org/wiki/Captcha.