Universal Description, Discovery and Integration (UDDI, pronounced Yu-diː) is a platform-independent, Extensible Markup Language (XML)-based registry by which businesses worldwide can list themselves on the Internet, and a mechanism to register and locate web service applications. UDDI is an open industry initiative, sponsored by the Organization for the Advancement of Structured Information Standards (OASIS), for enabling businesses to publish service listings and discover each other, and to define how the services or software applications interact over the Internet.
UDDI was originally proposed as a core Web service standard. It is designed to be interrogated by SOAP messages and to provide access to Web Services Description Language (WSDL) documents describing the protocol bindings and message formats required to interact with the web services listed in its directory.
UDDI was written in August 2000, at a time when the authors had a vision of a world in which consumers of web services would be linked up with providers through a public or private dynamic brokerage system. In this vision, anyone needing a service, such as credit card authentication, would go to their service broker and select a service supporting the desired SOAP (or other) service interface, and meeting other criteria. In such a world, the publicly operated UDDI node or broker would be critical for everyone. For the consumer, public or open brokers would only return services listed for public discovery by others, while for a service producer, getting a good placement in the brokerage—by relying on metadata of authoritative index categories—would be critical for effective placement.
UDDI was included in the Web Services Interoperability (WS-I) standard as a central pillar of web services infrastructure, and the UDDI specifications supported a publicly accessible Universal Business Registry in which a naming system was built around the UDDI-driven service broker.
UDDI has not been as widely adopted as its designers had hoped. IBM, Microsoft, and SAP announced they were closing their public UDDI nodes in January 2006. The group defining UDDI, the OASIS Universal Description, Discovery, and Integration (UDDI) Specification Technical Committee voted to complete its work in late 2007 and has been closed. In September 2010, Microsoft announced they were removing UDDI services from future versions of the Windows Server operating system. Instead, this capability would be moved to Biztalk.
A UDDI business registration consists of three components:
- White Pages — address, contact, and known identifiers;
- Yellow Pages — industrial categorizations based on standard taxonomies;
- Green Pages — technical information about services exposed by the business.