Flight simulators have advanced rapidly with the advent of improved electronics technology, and now there is a broad base of simulator types available for many types of training. From free and inexpensive desktop computer simulators such as the free open-source FlightGear and low-cost X-Plane and Microsoft Flight Simulator X to inexpensive motion-based training devices from Redbird and full-flight simulators from the big flight-training providers, simulation has had a profound effect on pilot training, and new technology promises even more advances in coming years.