Traditionally, electronic data interchange (EDI) has been effective for communicating transactions between companies, but only large enterprises performing a high volume of transactions have realised significant benefits using it. Now the Extensible Markup Language (XML) standard promises an open standard for secure, cost-effective business-to-business Internet commerce that will bring midsize and smaller companies into the fold. But the emerging standards landscape reveals it is not yet time to dismantle existing EDI and broker-based data infrastructures. Nevertheless, XML's pledge of better data portability among trading partners is the wave of the future.

Though EDI has been standardised through ANSI and EDIFACT (standards bodies), high implementation and operational costs, per-partner customisation requirements, and the need for value-added network providers have halted its widespread adoption. This, coupled with the fact that various standards bodies have moved at glacial speeds to adopt new standards, has spurred Internet-commerce software and platform vendors, merchandisers, and enterprise buyers to form consortia to tackle standardisation issues.

The World Wide Web Consortium (W3C) created XML to compensate for the shortcomings of HTML. HTML, a derivative of Standard Generalised Markup Language (SGML), employs a rigid set of rules that optimises browser-display document viewing. XML, judiciously pruned from SGML, retains SGML's power while reducing its complexity.

Unlike HTML, XML allows the document developer to create tags that describe the data, and optionally create a set of rules called Document Type Definitions (DTDs). Any standard XML parser can read, decode, and validate this text-based, self-describing document, extracting the data elements in a platform-independent way so that applications can access the data objects through yet another standard called Document Object Model (DOM).

For I-commerce software vendors and industry groups, XML's universal data interchange format offers a standards-based building block to use with other standards-based protocols, such as HTTP, TCP/IP, and the Internet. Support is already underway: Database vendors Oracle and IBM support XML natively; Version 5.0 of Microsoft's and Netscape's Web browsers understand XML; and Sun Microsystems considers the standard to be the portable data language for Java. Further, application servers such as Object Design's eXcelon offer XML capabilities for application integration, data interchange, and I-commerce.

Although the W3C developed the XML standard as the next-generation Web publishing language, IT developers realised the simplicity and power of this self-describing format and began to deploy XML in application integration projects involving disparate platforms and applications. This works well between two entities that understand the defined tags and their meanings; however, developers and vertical application vendors are developing their own DTD and schema flavours. The answer? Standards, such as OBI (Open Buying on the Internet) Consortium, commerceXML (cXML), Microsoft's BizTalk Framework, and RosettaNet's e-Concert set of specifications.

These standards are still evolving and mostly incomplete. Fast-moving RosettaNet is spurred by motivated participants with tough problems, and may be the first to reach the any-to-any I-commerce goal in the IT supply chain. Also, you cannot easily use cXML yet, unless you and all your partners use the standard by enhancing your enterprise resource planning systems or buying packages from vendors such as Ariba, or Veo Systems.

Momentum is clearly with XML as a portable data mechanism. The immediate benefit of XML-based e-commerce is that it will allow new and smaller businesses to participate; it's an easy sell, with its promise of simple implementation, wide availability, and lower costs. Even enterprises using traditional batch EDI should start looking at XML data interchange to include more partners and profit from resulting efficiencies. And IT managers should insist that enterprise resource planning vendors conform to standards rather than creating their own flavours du jour.

(Gess Shankar (gess@enooks.com) is an author, developer, trainer, and Webmaster with more than 30 years experience in IT.)XML glossaryDocument Object Model (DOM): An API defining a standard for developer interaction with XML-structured tree elements.

Document Type Definition (DTD): Written using a special syntax, DTD defines XML document structure and rules.

Schema: An enhanced alternative to DTD written in XML, the schema is more suitable for a data-intensive XML application.

XML parser: The parser reads a string of XML data, generates a structured tree, and validates data using DTD or schema.

Extensible Style Sheet Language (XSL): Written in XML, XSL contains instructions for getting data out of a document and converting it to another format.

Who does what(*)

XML standard

World Wide Web Consortium (www.w3.org/XML)I-commerce standards bodiesBiztalk.org (www.biztalk.org)CommerceNet (www.commercenet.com)cXML.org (www.cxml.org/home)OBI Consortium (www.openbuy.org)Open Applications Group (www.openapplications.org)RosettaNet (www.rosettanet.org)XML/EDI Group (www.xmledi.net)cXML/XML-enabled productsAllaire (www.allaire.com)Ariba (http://corp.ariba.com/corp/Home/default.asp)Commerce One (www.commerceone.com)Datastream (www.dstm.com)Extricity (www.extricity.com)Object Design (www.odi.com/excelon/Main.htm)Sequoia (www.sequoiasw.com/index.html)Vignette (www.vignette.com)XML-enabled platform vendorsIBM (www.ibm.com)Microsoft (www.microsoft.com)Oracle (www.oracle.com)Software AG (www.softwareag.com)Sun Microsystems (www.sun.com)Sybase (www.sybase.com)XML tools (not specific for I-commerce)Bluestone Software (www.bluestone.com)DataChannel (http://datachannel.com)Enigma (www.enigmainc.com)IBM (www.ibm.com/developer/xml)Microstar (www.microstar.com)(*) Not an all-inclusive listThe bottom line:

Extensible Markup Language

Summary: Text-based, self-describing XML-encoded documents may do for Internet commerce what HTML did for hypertext. Users now in the early adopter stage will bring about de facto standards.

Business Case: XML's extensibility and platform independence make it a powerful tool of convenience for the Internet. XML skill sets should be nourished not only for I-commerce but for other enterprise applications as well.

Pros

+ Extends I-commerce reach to include smaller partners+ Less expensive, more flexible than batch electronic data interchange+ Lets more applications tap into same interchange dataCons- Standards still evolving- Multiple proposals may cause incompatibilities- Documents much larger than in traditional EDI