Player provides a language-independent networked interface to robots and their sensors. Supported devices include Pioneer 2DX robots with sonar, odometry & compass, SICK laser rangefinder, ACTS color vision system, GPS, gripper and wireless communications. Stage provides a population of simulated Player devices. Controllers designed using Stage have been shown to work unchanged on real robots and vice versa. Stage aims for low-fidelity simulation of many devices, rather than perfect models.