This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
The application expires every two weeks and you will need to download it again.
I'm not sure about the license, the source code isn't available AFAIK. It is free now but I guess it is going to be a commercial product in the future.