Where are the "inner workings" of Exposé in OSX?

I need to alter the action of "App Exposé" in Lion so that it behaves like the old Exposé in Snow Leopard that showed all apps at once.

Does anyone know where I would find the files that control these actions?

I assumed the Dock since the Exposé app in SL appears to be a shortcut, but I don't have any luck finding something.

If you REALLY want to run old exposé, your only viable option is to downgrade to SnowLeopard.

More realistically, you may not know that if you do a two-finger swipe up over a stack of windows for an app in Mission Control, they spread out so you get a better look at them. In my experience this has always been enough to find what I need.

The other very useful thing is app exposé, if you map that to to a gesture you like then you really can always find the Windows you need in seconds.