RainCaptcha is a CAPTCHA class that does not require any image processing extensions (GD, ImageMagick, etc). CAPTCHA was developed to be readable by humans and resistant to OCR software. It generates black-and-white images with 5 distorted letters on them and noise. Its checking algorithm is case-insensitive.
Blur effect is an object that can apply the blur effect to HTML page elements. It takes the identifier of a given page element and starts an animation effect that progressively alters CSS properties of that element that make it appear blurred. Different CSS properties may be altered depending on the capabilities of the current browser. The object can also execute an animation that reverts the blur effect of the element. There are versions of the object either based or not in the jQuery library.
image_captcha will pull the images out of a user-defined directory and obfuscate them before rendering them to the screen. It will then allow the user to select the correct image via a select box or a radio button. This also allows the admin to choose the number of random words or filenames that will appear in the select box or radio field. Thumbnail support is available, in which missing thumbs are automatically generated from larger images and then displayed. Audio support is also provided for the visually impaired.