The ESB tier complements the WebLogic Application Server tier of the enterprise architecture by enabling already-defined EJB applications to be automatically re-purposed as Web Services. These services can then be published to, and consumed by, a wide variety of clients-not just Java. Presenting EJBs as Web Services means that they can readily be composed into composite applications and workflows with other services that may not be EJBs. Construction, integration, and use of these services does not require any EJB or server programming expertise-it is as simple, intuitive, and graphical as building Web pages. Therefore, significant additional service value (and new Web Services) can be added without incurring the cost and complexity of programming and delivering these exclusively on an EJB platform.