2D Flight Simulator
ACM
Airbus A340 Glass Cockpit
AirTraffic
atf2 Flight Simulator
Atlas for FlightGear
Aviascene
Aviation
Azure: Infinite Skies
BoozSimulator
Cambridge Rocketry Toolbox for Octave
CRJ Simulation
CRRCSim
Deep Space Pirates
EAFIT FlightSim
Elio's Flight Simulator
fgfs-qtgui
Fictional Air Combat
FlightGear
FlightGear Launch Control
FlightGear Scenery Designer
GL-117
GLRCSIM
Google Earth (Flight Simulator)
IFT
Java Flight Simulator
JFlightWizard
JSBSim
Kosmos
MiniFlight
MrATC
Open744 747-400 Simulator
Open Orbit
OpenSource RC Flight Simulator
Palomino 3D
Periapsis Space Flight Simulator
Phoenix OSFS
QFlight
RealTimeAirTrafficSimulator
RedShift Flight Simulator
SailAway
Search and Rescue
Silent Wings
SIM-Trek
Simulation Laboratory
Slope Soaring Simulator
SpaceFlight3D
SpaceWay
SuSim
TASim Flight Simulator
TaxiDraw
The Combat Simulator Project
The Flight Simulator
Thunder & Lightning
Valkyrie Simulation Project
Vega Strike
Virtual Air
XPC-777
X-Plane
X-Plane - ACFTools
X-Plane - airplanes
X-Plane - CRJ Simulation
X-Plane - FSOS
X-Plane - OpenEFB
X-Plane - Swiss ATC
X-Plane - Tools
X-Plane - xcharter
X-Plane - XHSI
X-Plane - XP2TS
X-Plane - XPC-777
X-Plane - XPIOCARDS
X-Plane - Xsens MTi-G IMU simulator
zSim flight simulator