Well..Just Download it Ok?...
Here's a list of some stuff you get in it:
Hidden Icons that Blizzard never used.
The Tree Models so you can make your own TREE UNITS
A hell lots of trigger including the Arrow movement system, The Save and load Hero system and a LOT of other triggers...(Cannot remember all of them)
You can have 16 tilesets in your map.
And a LOT more....