KinectBot’s software is hacked together just as much as its hardware. Robbel used simultaneous localization and mapping (SLAM) code from OpenSLAM.org (specifically GMapping) as well as some visualization packets from Mobile Robot Programming Toolkit (MRPT). He added his own interaction, human detection, and gesture code so that KinectBot could follow signed commands. As all of this is pretty much open (MRPT is GNU GPL, GMapping is Creative Commons, and Robbel’s own code isn’t anything MIT needs to keep proprietary) there’s a chance the software package will be available at some point for you to download.
The future of 3D vision hacking is bright!