Simple autoloader, customised the Zend autoloader to work with wordpress parent & child themes. Tries Parent and then fallsback to child. Could easily be reversed.

gistfile1.aw

function __autoload($class_name) {
    $parent_path = realpath(dirname(__FILE__).'/'.str_replace("_", "/", $class_name).'.php');
    if(file_exists($parent_path)) {
        require_once $parent_path;
    }
    
    $child_path = realpath( get_stylesheet_directory() . '/class/'. str_replace("_", "/", $class_name).'.php' );
    if(file_exists($child_path)) {
        require_once $child_path;
    }
}