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The XML Family
of Technologies
Interoperability and Resource Discovery: Theory
HTML markup is not as meaningful as we need it to be. Its <meta> tags are insufficiently
precise for searching, and as the number of Web sites grows the need to address this problem
becomes more and more pressing. Providers of Internet search engines continue to inves-
tigate ways to improve the accuracy and relevance of their Web searches.The shortcomings
of HTML and the ways in which it has been used to present content mean that the search
engines will never achieve the richness that would be possible were they in XML.
XML has been touted as an eventual solution to this problem.The Semantic Web,
explained in more detail below, is a proposed extension to the World Wide Web which
will allow automated querying and concentration of information based on meaningful,
machine-readable, XML-based semantic markup.
The Resource Description Framework (RDF) is another set of conventions used for storing
and conveying metadata in XML. It allows the interrelations and connections between
documents to be defined using dedicated metadata. RDF has been used on cultural
heritage projects, but its long-term future is uncertain.
The XML Wave
Where XML is Currently Used
XML has been adopted in numerous areas of business and cultural interaction. Given
its usefulness as a means of exchanging information between varying systems, the XML
wave has frequently been characterised as something more akin to an explosion.
has been used as a supplement and alternative to Electronic Data Interchange (EDI) for
e-commerce since mid-1999, and most online transaction now take place using some
kind of XML-based technology.
Although XML has been hailed as a significant breakthrough, there are at present sig-
nificantly more HTML pages discussing the benefits of XML on the Web than there are
XML Web pages. XML take-up has lagged behind the hype, but this is beginning to
change and the change is becoming more apparent.
What XML is Currently Used For
XML has a variety of uses, and its influence has been felt in every area of computing and
information science. For our purposes, these uses can be collected into three main groups:
- The exchange of data between applications;
- The execution of remote procedure calls (facilitating platform-independence);
- Data-storage, reuse, and repurposing.
Each of these purposes conjures up a whole world of possibilities, and the scenarios
and case studies that follow give a taste of what has been done, what is currently ongoing,
A growing A-Z list of XML industry sectors is maintained at
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