FlightGear is a free, open-source space and flight simulator used in aerospace research with flight dynamics (JSBSim) used in 2015 NASA benchmark to judge future sim code to NASA standards. 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.