Is this compatible with FSX, XPlane and others? Can it run simultaneously?

Absolutely.

VirtualPilot3D works as a standalone. It doesn't matter if you've installed FSX, Xplane or another other flight simulator.

It will work and run separately and it is compatible with any other flight simulators you have already installed.

Do note however that any add-ons for FSX, Xplane etc, will not work with our simulator.