FlightGear

FlightGear is an open-source flight simulator developed by the FlightGear team, offering a remarkably ambitious attempt to recreate civilian aviation on a wide range of computers. Players can fly numerous aircraft, explore detailed scenery, plan routes, and practice everything from ordinary takeoffs to considerably more complicated procedures. The simulator emphasizes realism and flexibility rather than arcade-style instant gratification, which means the first flight may involve rather more buttons than expected. Its open development model has allowed the project to grow through contributions from a large community. For aviation enthusiasts, that is excellent news. For everyone else, it means there are approximately seventeen switches to investigate before the engine agrees to start.

“The goal of the FlightGear project is to create a sophisticated and open flight simulator framework for use in research or academic environments, pilot training, as an industry engineering tool, for DIY-ers to pursue their favorite interesting flight simulation idea, and last but certainly not least as a fun, realistic, and challenging desktop flight simulator. We are developing a sophisticated, open simulation framework that can be expanded and improved upon by anyone interested in contributing.” - FlightGear team