On the PHP-GTK Community site, there's this post from Janosch Graf about a PHP-GTK desktop project (a desktop environment inside of a PHP-GTK shell) called php-desktop.

php-desktop emulates a desktop using KDE programs/icons

php-desktop is tested with KDE. It also uses KDE programs (for example kde-open) and KDE icons. php-desktop gets the icon by the mimetype of a file. If the file is a desktop-file php-desktop gets the icon from there.

You can check out a screenshot of the project for a preview of what it's like or just download the archive and try it out for yourself.