The traditional enterprise is experiencing numerous technology challenges, the most recent of which are the results of new business paradigms (e.g., the Internet, the World Wide Web, economic pressures, and global e-commerce). Adding further complexity are traditional development practices, vertical system development, lack of support for data standards, acquisition of diverse businesses and technologies, and the implementation of software packages. These challenges beg for solutions that include cross-platform exchange and sharing of enterprise data.

Today's typical business enterprise is often composed of several autonomous business units. Often, each of these business units and their supporting systems has its own definition of mission-critical data. Regardless of the supporting technology, the business concept of a customer, vendor, or product processed by one system is of the same general context as that of the other systems. However, at a granular level the data characteristics of these business concepts tend to vary widely. These data characteristics are known as metadata. Perhaps the most often quoted definition for metadata is "data about data." Actually, metadata goes well beyond this simple definition to include the format, rules, and constraints that describe data.

eXtensible Markup Language (XML) has recently gained much notoriety as a technology solution. It can be used to advantage for many different types of applications such as moving data between different business systems or describing a business transaction, a request to persist or store data in a database, or a service request. By virtue of being platform agnostic, transactions and data exchanges are...