Fedora 15 now includes the Robotics Suite, a collection of packages that provides a usable out-of-the-box robotics development and simulation environment. This ever-growing suite features up-to-date robotics frameworks, simulation environments, utility libraries, and device support, and consolidates them into an easy-to-install package group. See http://fedoraproject.org/wiki/Robotics for more details.
Player is a free and open networked robotics server. The Player server acts like a "robot abstraction layer," providing standardized interfaces and messaging management for many classes of robotics-related devices (camera, ranger, planner, etc.) Drivers for individual devices abstract information into these interfaces and use them to communicate amongst each other.
Fawkes is a component-based software framework for robotic real-time applications for various platforms and domains.
Stage is a free and open 2.5D robot simulator. It can be used on its own, or as an extension of the Player robot server. Stage supports simulation of vehicle movement, and various sensors such as scanning laser range finders, SONAR arrays, cameras, fiducial markers, etc.
RoboCup Soccer Simulator
The RoboCup Soccer Simulator(RCSS) is a research and educational tool for multi-agent systems and artificial intelligence. It allows for two teams of simulated autonomous robotic players to play soccer (football).