 Microsoft
Microsoft has been working quietly for some time now (very little publicity) on its 
Robotics Developer Studio software.
And, it has announced a major 
shift in strategy: from now on Microsoft RDS will be 
FREE.
By making software available for everyone to download, the Redmond company hopes to promote and speed up the development of robotics applications among researchers and developers.
RDS is not an operating system for robots but rather a 
visual programming interface with tools and a 3D simulator.
It works particularly well with platforms Create by iRobot, LEGO Mindstorms, CoroWare and Parallax.
However, Microsoft's RDS software is not alone in this niche.
It also faces competition from Urbi by Gostai (France), ERSP by Evolution Robotics, the 
Player-Stage project and 
ROS by WIllow George.