"ESP" stands for "electronic stability program" or "electronic stabilization program." ESP is essentially automotive extrasensory perception, as it allows the vehicle to read the road and use the anti-lock brake system and traction control to stabilize the vehicle.
ESP is the general acronym for this type of system, but different car manufacturers have their own names for their own systems. For example, General Motors refers to their program as Stabilitrak and Nissan calls its program VDC, for vehicle dynamic control. Regardless of what it is called, the ESP program essentially reduces the potential for over- and under-correction when a driver responds to a road hazard.