The DC-9 Classic comes with these 6 liveries in the release package:
Failure simulation. This is what in my opinion takes the DC-9 Classic, and all other addons that includes such a feature, to the next level. Usually when you simulate a system in an aircraft, you simulate ON or OFF in a normal state. With failure simulation a system can also be simulated ON or OFF in a failed state. While OFF is usually OFF regardless of state, ON and failed at the same time is where it can get really busy real fast on the flight deck.
Dovetail Games. The latest contender trying to make move to take over the flightsim throne from FSX. Can they do it? Do we even care? I think we should care. And I think they can.
Günter Steiner from the LINDA project is currently working on a LINDA module for the DC-9 Classic.
LINDA is an interface that sits between the aircraft and your hardware (joystick or other input device) and makes assigning swiches as simple as possible.
You can read more about the LINDA project at fs-linda.com.