15. The method of claim 11, wherein said determining differences includes matching said first plurality of objects of said first graphical program with said second plurality of objects of said second graphical program.
15. The method of claim 11, wherein said determining differences includes matching said first plurality of objects of said first graphical program with said second plurality of objects of said second graphical program. 16. The method of claim 15, further comprising: creating data structures to represent said first and second graphical programs, wherein said matching uses said data structures.