Photopia was created with Inform and has IFID FA808027-B64E-4C15-A3F2-2B7B1EC71E52. To play a work like this one, you need an interpreter program: many are available, among them Zoom
for Mac OS X and for Unix; Windows Frotz or Windows Glulxe for Windows.
Or you can play without downloading anything by following the 'Play In-Browser'
on your web browser.