"Where Are You Going, Where Have You Been?" Developed by OASIS (oasis-open.org) As the name says, provides Descriptions of services, and ways to find and use them. No support built in to PHP, but...UDDI is used via SOAP. The UDDI specifications define Web service interfaces to allow programmatic access to the UDDI registry information. The UDDI API is based on SOAP (Simple Object Access Protocol) which provides a synchronous RPC mechanism to UDDI. All UDDI registry Operator sites will support all the UDDI API calls. The UDDI API is divided into two logical parts: Inquiry API: Provide programs with the capability to locate candidate businesses, Web services and then services, and drill into the specifics based on overview information provided in the initial calls. The Inquiry API functions are exposed as SOAP messages over HTTP. No authentication is required to make use of the Inquiry API functions. Publisher API: Enables programs to save and delete each of four data types supported by UDDI. Authenticated access is required to use the Publisher API, i.e. the user must first sign-up with one or more operator sites to establish user credentials. Source: http://wwws.sun.com/software/xml/developers/uddi/