JSBSim is an object-oriented (C++), multi-platform, 6-DOF, Flight Dynamics Model (FDM). It can be run as a standalone, batch-mode flight simulator (no graphical displays), or integrated with FlightGear or other flight simulator.
The aircraft models included in this project and distribution do not include any proprietary, sensitive, or classified data. This should be rather obvious. All data is derived from textbooks, freely available technical reports, or other public data.
Likewise, no proprietary code is included. All code included within JSBSim has been developed on a volunteer basis using publicly available information, and is often directly linked to a particular textbook, for educational reference.