QapTcha is a draggable jQuery captcha system with jQuery UI.

QapTcha is an easy-to-use, simple and intuitive captcha system.
It needs human action instead of to read a hard text and it is a very lightweight jQuery plugin.

In order to work with iPhone and iPad, a file jquery.ui.touch.js has been added in v2.5

QapTcha works with PHP5.2 or more cause to the function json_encode()