messaging uses SOAP with extensions, and implementation interoperability ploughs the same ground as WS-I. NOTE Version 2.0c of the ebXML Message Service Specification consists of core Packaging Specification, ebXML SOAP Envelope Extensions, Error Handling, Security, and SyncReply elements. The spec also offers additional features, such as reliable messaging, message status service, message order, and multihop message routing. You can read the ebXML position paper and view accompanying slides at http://www.w3.org/2001/03/ wsws-program.  This  page  for  the  April  2002  W3C  Web  Services  Workshop  has  links  to  several  other presentations and position papers that involve interoperability issues. Sun Microsystems is an outspoken proponent of ebXML, which competes with Microsofts BizTalk Server and the BizTalk Framework. A third-party BizTalk adapter produced by iWay (http://www.iwaysoftware.com) provides ebXML registry services; the iWay Transformation Engine supports ebXML and EDI messages. XML.orgs Schema Registry XML.org is a portal site hosted by OASIS at http://www.xml.org. The stated purpose of XML.org is & to minimize overlap and duplication in XML languages and XML standard initiatives by providing public access to XML information and XML [s]chemas. The XML.org site provides a registry search service at http://www.xml.org/xml/registry.jsp that lets you specify the document type, such as XSD, XDR, or DTD. Try a search on a keyword thats specific to your industry or service. The search page also has direct links to about 100 ebXML specifications classified by industry. TIP XML.org and OASIS host Robin Covers Cover Pages (http://xml.coverpages.org/sgmlnew.html), which publishes news on SGML and XML topics. The Cover Pages provide the most up-to-date and detailed information on activities that relate to XML Web services. BizTalk.orgs Schema Registry BizTalk.org is a Microsoft-sponsored Web site (http://www.biztalk.org) intended to & provide resources for learning about and using Extensible Markup Language (XML) for [e]nterprise [a]pplication [i]ntegration (EAI) and business-to-business (B2B) document exchange. The content of the site consists primarily of propaganda for BizTalk Server and the BizTalk Framework. The site also offers a registry of close to 500 user-contributed schemas, almost all of which are in Microsofts proprietary XDR format. As the BizTalk community gradually moves from XDR to the XSD format, you can expect the percentage of contributed XSD schemas to increase. BizTalk Server 2002s BizTalk Framework 2.0 supports SOAP 1.1, and XML Schema 1.0 Parts 1 and 2. BizTalk Server 2000+ includes an XDR to XSD conversion script. C  h  a  p  t  e  r 1  2  : I  n  t  e  r  o  p  e  r  a  t  i  n  g w  i  t  h T  h  i  r  d  -  P  a  r  t  y W  e  b S  e  r  v  i  c  e  s 4 4 7