Exporting and comparing AD Schema change

Does anyone know how to compare before and after snapshots of the AD schema when installing a product that will modify it? My customer is concerned about the schema being modified by a ?Cognos? product. My feeling is there has to be a way to do this in a test environment and export the schema before and after the changes. Then run a utility on them to find out what has been changed or ?modified?, although modifying an existing object in the schema would be extremely stupid on Cognos part, I still need to verify that its not doing it.