Webfiles on PirateBox

Hi,

I'm just new to PirateBox and was doing some reading. Tomorrow i'm going to buy myself a wireless usb dongle and try it out!
I got this great idea for a mod (sorry can't share yet), so I was wondering: How does the PirateBox web-interface work? Is it based on PHP? Or are those plane HTML files?

Thanks in advance,
M2xpow3r