What does this have to do with node-webkit? My understanding is that nodejs is a subset of node-webkit, so by saying "this is for nodejs", you imply "this is for node-webkit".
That's true, but I want to stress Node Webkit because NW apps are probably one of the best usecases. Also, there is a bit of helper code specific to Node Webkit, so that you don't need to worry about where the data is stored.