Thank you for writing.
Currently, the demo application is using custom collapsible panel control developed especially for it. The good news is that we have made an official implementation of this control which will be out with our very next release which should be out in a week or two.
For the other part the control used is RadPanorama. More information about this control can be found in the following help section: Panorama
If you have any questions, please do not hesitate to contact us.