[Reprinted from The Times Higher Educational Supplement (May 7 1999), page 21.]
XML (Extensible Markup Language) is seen as the "next thing after HTML" and interest in it is growing fast. Last week 1000 of the leaders in this new field met in Granada to discuss this next generation of web-based technology and to show the products which already support it. It will have a major impact on web-centred education, and as one of the few academics in Granada I feel we need to know more about it.
Microsoft has included XML capabilities in its new browser, Internet Explorer 5. In a keynote speech Microsoft's Adam Bosworth showed how a custom application can be built to include both traditional "documents" and structured "data" in a completely integrated fashion. It is the need to support e-commerce that is driving XML and we will all benefit from the tools being developed. Bosworth showed how XML can be used in a browser environment to support the management of student records. Microsoft is committed to supporting XML in all its new software including Office2000.
The good news is that XML is a non-proprietary standard, backed by the World Wide Web Consortium (W3C), and all the big players are involved. Thus IBM has an excellent range of freeware (http://www.alphaworks.ibm.com) including nice authoring software (Xeena) and many other useful tools for filtering documents. Creating your resources in XML is a big step towards "future-proofing" them.
XML can be viewed on screen like a document, and processed automatically like a database. Since it lets you design your own tags, it is easy to build documents with <STUDENT>, <TUTOR>, <CLASS> and other relevant concepts. A <STUDENT> can have properties (attributes) such as <CLASS> and <TUTOR>. There are already good authoring tools for XML, including good freeware, so academics can easily create such records easily once an appropriate document design (known as a DTD, soon to be extended to XML Schemas) has been set up. The XML Query Language (XQL) allows these documents to be queried in a very flexible manner - we can ask which <STUDENT>s attend this <CLASS> and had marks greater than 65 per cent. XSL, the Extensible Stylesheet Language, lets you present this in any format you wish - Word/RTF, say, or HTML, TeX or Postscript.
However the major benefit for academics will be in creating your own teaching and learning resource material in XML. I gave a pre-meeting tutorial and created my "slides" and examples directly in XML. I was able to display them in HTML, and print them out in RTF/Word. More importantly, I can now re-use selected parts of the material in different situations: a public lecture, a specialist postgraduate course or a first-year undergraduate module. For example, it is easy to use XSL to filter out advanced material tagged <SECTION level="expert">.
Navigation is a critical problem in large collections of electronic documents, and though a hierarchical system often works well it cannot support multiple "views". The conference proceedings have been produced in XML and analysed using "topic maps", a draft ISO standard for knowledge management. We could browse the proceedings through topics such as subject, author, industry. The World WideWeb Consortium is developing XLINK to support robust generalised hyperlinking (hypermedia) and I am confident that we shall see powerful tools very shortly.
Domain-specific markup languages are now becoming robust and vendors were displaying MathML tools for mathematics. Vector graphics, currently a standards battleground, will soon be united in Structured Vector Graphics (SVG) which allows complex scalable drawings, with embedded hyperlinks, to be transmitted over low bandwidth connections. Many academic disciplines have been waiting for something to replace the inadequacies of GIFs and bitmaps.
Chemical Markup Language (http://www.xml-cml.org) is also completely interoperable with all XML protocols and tools.
In the Virtual School of Molecular Sciences we shall be using XML to create a CD-Rom of course material on protein structures and drug design. We shall also be converting our students records to XML and using it for our electronic submission of student work. It will make an enormous difference.
Peter Murray-Rust is professor of pharmaceutical sciences, University of Nottingham.
Prepared by Robin Cover for the The SGML/XML Web Page archive.