Please notice that this is ArduPilot Mega 2.5 Fully Assembled Kit With GPS indeed.
ArduPlane is the Arduino-compatible open source software used by the ArduPilot Mega (APM) autopilot to control fixed-wing aircraft. ArduPlane provides an entire UAV control system with sciptable missions, 3D waypoints, in-flight uploading of commands and powerful ground station software.
And now come up that The ArduPilot Mega 2.5 is a complete open source autopilot system, with no assembly required. It allows the user to turn any fixed, rotary wing or multirotor vehicle (even cars and boats) into a fully autonomous vehicle; capable of performing programmed GPS missions with waypoints.