I've been playing with a Raspberry Pi and I have this project that might use the GPIO pins, I've poked around to see if any Ruby gems allowed me to use it, I've found this good one that has an event driven way of doing it.
However later I decided to use a Piface instead of the pins directly, unfortunatly there were no event driven gems for piface, which is a shame, because I figure it's the best way to interact with it. So I made one.
I've based of piper because all the threading stuff was already done, hope it helps more people with piface projects.
Oh yes, Ruby 2.0.
pi_facer on github, pi_facer on rubygem.