XML Web Services Directories
As with any other resource on the Internet, it would be virtually impossible to find a particular XML Web service without some means by which to search for it. XML Web services directories provide central locations where XML Web service providers can publish information about their available XML Web services. Such directories can even be XML Web services themselves, accessible programmatically and providing search results in response to queries from potential XML Web service clients. It might be necessary to use an XML Web services directory to locate an organization that provides an XML Web service for a particular purpose, or to determine what XML Web services a particular organization provides.
The UDDI (Universal Description, Discovery, and Integration) specifications define a standard way to publish and discover information about XML Web services. The XML schemas associated with UDDI define four types of information that would enable a developer to use a published XML Web service. These are: business information, service information, binding information, and information about specifications for services.
As a core component of the UDDI project, the UDDI Business Registry allows businesses to programmatically locate information about XML Web services exposed by other organizations. Developers can use the UDDI Business Registry to locate discovery documents and service descriptions. For more information, see the UDDI Web site (http://uddi.microsoft.com).