This Engine is a powerful asset that creates lights and shadows using a composition of surfaces.
It's not powerful like a shader, but still a very good approach, being totally configurable, easy to learn and it's very optimized. That means: FAST!!!
It's based on flokkienathur algorithm, but with a huge quantity of improvements.
You can download the "dancing skeletons" demo here: http://bit.ly/1DlowCn