The demo was running on a MacBook with Parallels desktop, using a cut-down Linux/Knoppix distribution called Buildix, which runs Trac, Cruisecontrol and Subversion out of the box. The goal of Buildix is to provide an out-of-the-box project management environment that can run either on a desktop, or alternatively on a virtual system like a Xen or Parallels VM image. Of course, if you're running several different VMs on the same MacBook, you'll need to load it with RAM.
The demo was set up to show Selenium running, so that a modification would kick cruisecontrol off, which in turn would run selenium across many browser configurations (Mac OS X/Safari, Windows/IE, Ubuntu/Firefox) -- all on the same machine. However, as is often the case in such environments, the demo didn't quite work out and we were treated to pre-recorded demos (always a good idea to have pre-canned demos on hand in case the live demo doesn't work out; although, it's also worth checking that you have the network cable plugged in ...)
The other cool thing that the demo used was pyvnc2swf, which uses VNC to record into a SWF (Flash) file for later playback. The demo had setup options to automatically playback and record into a SWF file, and optionally commit it to subversion for later access (though with the size of flash files, it might not make sense to store historic versoins of this file). The video is now available.