It seems to be flash made but I would do it in Java.
Jquery could do just the same thing and faster.
Check out this page for a bunch of tutorials 38 jquery and CSS drop-downs and a few more 13 Tutorials.
Maybe this one is the closest to what you are looking for Multi level drop-down It is all a matter of changing the animation settings to how you want it.
If you wanted the exact menu, I'm sorry. I can't help with that.
Hope I helped.