the IBOutlets make it possible to set the delegate and the dataSource directly in IB, like it's possible for standard UI elements like UITextField. It's just for convinience, the charts can be used without the IBOutlets, too.
![screenshot 2014-05-05 10 33 56](https://cloud.githubusercontent.com/assets/7364108/2876168/06cb68fe-d430-11e3-94f7-bb6c407176c2.png)