It has 128MB RAM, a Via C7 CPU and 64MB (yes, megabyte!) of flash storage on board which is used for swap.
It runs an X server and on boot it ssh's into adminstuff and runs chrome with the chrome window displayed on the kiosk, it then goes to this  section of the london hackspace website for the UI.
There is also some code that talks to the card reader and pastes any card uid's found into a hidden field on the web page.
If the kiosk gets restarted you'll need to click the mouse once on the chrome window for it to get focus (or be activated or brought to the foreground or something like that) before it will read cards.
It also runs waspd from here: https://github.com/londonhackspace/wasp-label-printer to talk to the printer.
Obsolete code that is not used here: https://github.com/londonhackspace/enrolment