There's one more free/open robot operating system option out there today. Jean-Christophe Baillie of Gostai SAS writes, "I thought you might be interested to know that the Urbi Operating System for robotics is now going open source.". If you're familiar with Urbi, you may know that the component architecture and library code have been free software licensed under the GPL but the actual Urbi kernel has been proprietary up until now. With this announcement, the kernel is being relicensed under the Affero GNU GPL v3, allowing it to join the other components as free software (or open source software if you prefer). All the free software components are also available for download at no cost, making them free as in free beer as well as free as in free speech. The one missing piece that remains is Gostai Studio, a GUI programming environment for Urbi. We can hope that too will be freed before long or a suitable free software replacement developed. Urbi supports the Sony Aibo, iRobot Create, LEGO Mindstorms NXT, Aldebraran Nao, MobilRobots Pioneer, Segway RMP, Meccano Spykee, and other robots.