Moot Isn't the Domain model simply composed of many data models? Data models are therefore complementary to the domain model and not contradictory to it. Perhaps I'm not understanding the point you are trying to make. At some point the data has to be represented in some malleable form that people can work with and exchange. Since XML is standards based, transport, language, OS and development platform agnostic I think it's an excellent choice. Sure XML has it's warts like anything else but I think the positives far out way the negatives. Kevin