This is nothing more than a file sharing device with a GUI. It allows any users capable of connecting to a wifi network to be able to file share anonymously. The PirateBox doesn't log any information, has chat built in and allows users to hosts and exchange files locally without the use of an FTP or separate hosts. P2P local share.

Maybe the DIY page will clear it up for you. It is pretty basic stuff, but looks very well done.
http://wiki.daviddarts.com/PirateBox_DIY