XML is coming to the rescue. The Extensible Markup Language is a World Wide Web Consortium (W3C) recommendation, finalized in 1998, that has been widely adopted around the world. By now most of you have been exposed to XML either through actual projects your organizations are undertaking or through pressure you are probably receiving as to why your organization hasn’t started the move to XML. You can see on the slide the example of how an XML tag is used to specify a social security number. A software agent can read the XML tag and know unambiguously that it is dealing with a social security number and not a phone number, a part number, or any other kind of a number.
	There are a large number of communities of interest that are developing their own XML dialects. An XML dialect is basically just an agreement within a general area on the XML terms that will be shared across that community.
	XML is great and many applications are being developed to take advantage of this new lingua franca of the web. It does have a limited capability to express complex relationships between information objects. XML only supports “contained in” or “parent-child” relationships, such as an <address> may contain sub-elements of <street number>, <street name>, <city>, <state>, and <zip code>.