One of projects I've been working on is Webconverger. Webconverger is an open source Linux-based kiosk that uses a customized version of Firefox as the user interface.
Webconverger is a great choice if you are setting up a kiosk or digital signage. It can be quickly and easily deployed on any type of machine. It works especially well on legacy hardware because of its low resource requirements. It can even be installed onto a USB stick and simply plugged in to an existing machine.
The configuration for the kiosk is downloaded from a server allowing you to customize your kiosk remotely and it will pick up your latest changes. It has a full featured API that allows you to do things like customize the browser chrome or whitelist certain sites. Plus it even stays updated automatically if you choose by downloading the latest version in the background.