Profound UI supports PHP as a server-side language for driving Rich Display Files. Before getting started, please make sure that you've installed Zend Server for IBM i.
Enabling PHP using the Profound UI Installer
You can then enable PHP during the installation process by selecting the "Enable Zend PHP" checkbox in the dialog under the "Customize..." button. Once the checkbox is selected, you should confirm the appropriate location for where Zend server is installed.
Enabling PHP manually
To enable PHP manually, you can see how to create a combined Profound UI and Zend Server configuration here.