"Separating the logic necessary to display information from the logic necessary to store, validate and process information is always a grand goal, a goal I believe in, and a goal that PTE embraces."
Why is PHP Code Considered Hard to Maintain?
tppAJAX is a lightweight, yet feature-rich PHP and Ajax toolkit that is compatible with PHP versions 4 and 5. There are two components to tppAJAX - the client-side library written in Javascript and the server-side library written in PHP.
This is an ASCII CAPTCHA that uses no image libraries - an online demo is shown. Very effective and priced well.