21. The method of claim 15, wherein said determining differences includes comparing matching objects in said first graphical program and said second graphical program to determine differences in said matching objects.
21. The method of claim 15, wherein said determining differences includes comparing matching objects in said first graphical program and said second graphical program to determine differences in said matching objects. 22. The method of claim 21, wherein each of said first plurality of objects and said second plurality of objects comprises a set of attributes and methods, wherein said comparing matching objects includes comparing attributes of said matching objects in said first graphical program and said second graphical program.