e2001 Your Digital Future - Bangkok Post Special Supplement

INTERNET TRENDS

XML will be the foundation for future computing

Computer industry agrees on standard

Tony Waltham

The IT industry seldom agrees across-the-board on a particular computer language or code. But when it comes to XML, which stands for Extensible Mark-up Language, all seem to agree, from Microsoft to Sun Microsystems, from Oracle to IBM, that this will be the foundation for our future computing experiences.

XML is a data format for structured document interchange on the Web and, like HTML, it is a markup language derived from SGML and it is best suited for organising data, according to comprehensive background information that can be found at the XML-zone web site <www.xml-zone.com>.

It is an industry standard under the World Wide Web Consortium (W3C) and version 1.0 of the specification was accepted in February 1998, while it is still evolving. (For specifics see the W3C site <www.w3c.org/xml>)

The development of XML is a public project headed by the World Wide Web Consortium (W3C) and is not owned by any one company, with an XML Working Group in charge of development of the official specification.

While HTML specifies how a document should be displayed, it does not describe what kind of information the document contains, or how it is organised. XML fills this void and allows document authors to organise information in a standard way.

XML was designed to be a "an extremely simple dialect of SGML" and because it is a SGML subset, all valid XML documents are also valid SGML. It is cross platform and a text-based, non-binary format that uses syntax rather than binary markers to organise data so it can be used on just about any platform.

Nor is it limited to Internet use. Its information organising ability makes it perfect for exchanging data between different systems, regardless of whether the Internet is part of the picture.

While dedicated XML authoring tools are beginning to appear, since XML is just text, any editor or program that can generate text files can be used to create XML documents.

Viewing XML documents requires a program called an XML parser, and both Microsoft and Netscape are working to add this capability to their browsers.

Related to XML is XSL, which stands for eXtensible Style Language, which is used in a way similar to HTML's Cascading Style Sheets (CSS). It can be used to transform XML documents into HTML using rules based on the XML document's structure and tags. Once an XML document is converted into HTML using XSL, it is viewable in any browser.

E-commerce can benefit from XML by enabling back-end systems to communicate business transaction information in a known format. For example, business partners can standardise on specific XML syntax they use to describe purchase orders and can then automate the transfer of that information across otherwise incompatible systems.

It is also a good complement to Electronic Data Interchange (EDI) and the XML/EDI Group <www.xmledi.com> is working hard to standardize the XML syntax for EDI documents, having recently submitted an e-commerce related Document Type Definition (DTD) to the W3C for consideration as a standard.

XML-related tools are available for just about any platform and many are free. The SGML/XML Web Page at <www.oasis-open.org/cover/publicSW.html> maintains a very thorough list of publicly available software for XML.