This is an Arduino-based Web Server library, originally developed for a class at NYC Resistor. It's called Webduino, and it's an extensible web server library for the Arduino using the Wiznet-based Ethernet shields. It's released under the MIT license allowing all sorts of reuse. I've also put my not-quite-complete presentation up for viewing at https://docs.google.com/presentation/d/1QUG4XJTK3jKtU-eYUfM1DvUdRaKBrp__LEwZQfz9s6E/edit#slide=id.i5
I've got a few examples up right now -- the Buzz example interfaces with Zach's Danger Shield allowing you to remotely start and stop the speaker. We had a room full of students pinging my Arduino board on Saturday, buzzing me while I was lecturing. It was fun. The big Demo example shows how to setup an HTML form running on the device where you can read and write pins.
I hope to add a few more examples in the next few weeks, including a web-enabled fridge sign using a serial LCD and how to serve things other than just HTML text from the device. I also need to work on more documentation and finishing up my slides.