tributed and programmatically accessible over standard Internet protocols. The Worldwide Web Consortium (W3C) has a more technical definition: A Web Chapter 8 - Next-Generation OSS service is a software application defined by a URI, whose interface and binding are capable of being defined, described and discovered by XML artifacts and supports direct interactions with other software applications using XML-based messages via internet-based protocols. In any event, Web services are reusable components that communicate via well-defined interfaces and internet protocols. These services provide a standard means of communication among different software applications and promote interoperability and extensibility among applications. The Web Services architecture specifies several technologies and concepts: Standard Internet Protocols: Web services are usually built on ubiquitous Internet infrastructure, especially the connection protocol of the Web - HTTP. Extensible Markup Language (XML): XML, the widely accepted protocol for sharing structured documents and data on the Web, is the lingua franca of the Web services stack and is the building block for almost everything else in the services stack. Simple Object Access Protocol (SOAP): SOAP is a protocol specification that defines a uniform mechanism for passing XML-encoded data. It also defines a way to perform remote procedure calls (RPCs) using HTTP as the underlying communication protocol. - Web Services Description Language (WSDL): WSDL provides a mechanism for describing the basic format of Web service requests over different protocols and encodings. WSDL is used to describe "what" a Web service can do, "where" it resides and "how" to invoke it. Universal Description, Discovery and Integration (UDDI): UDDI provides a mechanism for clients to dynamically find other Web services. It includes a set of protocols and a public directory for registration and lookup of Web services and business processes. It can be thought of as a DNS service for business applications. Web 