FlightGear is an open-source flight simulator developed by an international team of volunteer coders and enthusiasts. It is one of the most comprehensive and realistic flight simulators available, allowing users to fly a variety of aircraft in a 3D environment. FlightGear offers a wide range of features, including a detailed global terrain database, realistic flight dynamics, a variety of aircraft types, multiple views, and detailed instrument panels. It also provides a number of scenarios, missions, and tutorials to help users learn how to fly a plane. FlightGear also has a thriving online community, allowing users to share their experiences and collaborate on new projects. FlightGear is available for free for Windows, Mac, and Linux operating systems.
Microsoft discontinued confirmed the closure of the ACES studio, the development team of Flight Simulator, on January 26, 2009. Anyway, Flight Simulator X is still available on Microsoft Store.