In the last two installments of my Thinking XML column, I covered semantic transparency -- the ability to share the meaning of the bits that go between those freewheeling XML angle brackets and quotation marks. Recent events in XML directly touch on the topics I covered, so in this installment (and others from time to time), I'll divert from the primary line of discussion to provide an update on these developments.
Much of the effort toward semantic transparency has been in the area of trade facilitation, which is understandable as organizations, in their elusive quest for transaction automation, probably have the most to gain. There is a flurry of activity in this area, and I'll take a look at ebXML and a project involving RosettaNet.
I was at the recent XML DevCon in New York, and ebXML was everywhere. In fact, one of the conference themes was the global coverage of ebXML. It was good to hear ebXML boosters discuss the importance of ebXML for organizations -- including small enterprises in industrial nations and non-governmental organizations (NGOs) throughout the world -- that can't afford the cost in time or effort to join trendy e-business consortia. Just as cellular and satellite communication has been a boon to developing nations that lack the resources to build their technology infrastructure the way it was developed in the West, XML-based trade and business-process facilitation has the potential to provide the sorts of productivity gains that would otherwise only emerge after long evolution of information technology. As U.N. Secretary General Kofi Annan says:
Information technologies can give developing countries the chance to leapfrog some of the long and painful stages of development that other countries have had to go through.
An important statement of principle made by the ebXML folks at the New York conference was that ebXML is meant to be "loosely coupled." This means that it is very flexible when handling technological differences on either side of a trade interaction. This is a very important principle because the entire value of Web services, beyond buzzword coinage, is to succeed in allowing application logic to operate across organizational boundaries where remote procedure calls and distributed objects have failed. Unfortunately, many of the technologies developed for Web services look more and more like the same old component platforms dressed up in XML and HTTP. As ebXML proponents point out, this raises the danger that Web services will rely on tight coupling. Of course, tight coupling tends to serve vendor hegemonies better. Almost every technique used by vendors to lock in customers relies on the tight coupling of different aspects of the customer's systems, so the fight for loose coupling may be against great odds. As an example, the adoption of SOAP as ebXML transport could be considered a telling loss in the fight for loose coupling.
At the conference I looked for signs that these are not just idle principles in search of products. To that end, I found concrete examples of ebXML in use. One pavilion housed vendors who were showing off products implementing ebXML. Also, the conference was one of the stops on the ebXML proof of concept (POC) demo road show. The likes of NetFish/IONA, Documentum, Sun, BEA, Commerce One, Fujitsu, Kildara, and Bowstreet got together with their ebXML prototypes (written in Perl, Python, C++, or Java) and demonstrated their ability to send messages transparently to each other's software, including demonstrations of intermediary systems. Following the demo, conversations with some of the participants indicated that this code is moving quickly from prototypes to shipping packages.
The big news in ebXML emerged just before this article went into production. On May 14, ebXML completed its 18-month development cycle and was ratified by its parent organizations for use in trade. The announcement included a long list of core specifications that have been approved, and it stated that the initiative will now turn the majority of its effort to driving adoption. There will be plenty of time to assess ebXML in terms of market and technical success, but the very delivery of such a comprehensive body of specifications, and the diversity behind its development, is excellent news for XML adoption in the area of communication among organizations.
The ebXML folks at XML DevCon were also touting their collaboration with vertical XML vocabulary initiatives including Automotive Industry Action Group (AIAG), Global Commerce Initiative (GCI), and OpenTravel Alliance (OTA); collaboration with Health Level 7 (HL7) is apparently in the works. Of greatest interest was their mention of a collaboration with RosettaNet, with emphasis on hosting RosettaNet PIPs in ebXML Registry/Repository. (For an explanation of these terms, see my last column installment.)
Despite this convergence of efforts, one conclusion that may be drawn from my listing of XML vocabulary initiatives in this column is that there is excessive fragmentation in the semantic transparency space. Through a recent press release, RosettaNet made a public statement voicing this concern and their earnest desire to unify the churches:
Although many of the XML initiatives today are complementary, the sheer number of XML standards efforts is leading to confusion amongst implementers and key decision makers alike. To provide a clearer understanding in the industry, RosettaNet has developed a conceptual model for defining the layers of XML standards required to support B2B integration between trading partners across supply chains.
This conceptual model highlights the choreography of business process, business and technical dictionaries, and messaging services as the components needed for e-business. The document goes on to describe this model in some detail. Unfortunately, once it turns to the details, the press release seems to waffle on the specifics of how RosettaNet will work with other initiatives to bring its concepts to reality.
I've written a great deal about the things that large, gray consortia are developing in the cause of XML semantics. As usual, some of the most exciting work in the area comes from smaller, more intrepid groups. WordNet, a project hosted by Princeton University, has created a structured database of words and synonyms linked by their semantic relationships. The openness and machine accessibility of WordNet have made it a favorite source for software navigating semantics. Indeed, there have been a lot of initiatives to make WordNet accessible to RDF tools, which I've mentioned in the Resources section.
For a nice example of this WordNet surfing, see Dr. Jonathan Borden's online browser, which uses Dan Brickley's online RDF WordNet model. The browser is driven by XSLT stylesheets and should therefore serve as a handy tool for developers who are exploring practical systems for semantic associations until this column returns to the topic. The only problem with the online browser is its sluggishness, but for faster access, you can download WordNet RDF dumps to local machines.
Every few months, this column will turn its attention to current events and interesting new projects. If you know of any such developments that are worth passing on, please let me know. Next month we return to the schedule of knowledge-management topics.
- Thinking XML: XML meets semantics, Part 1 and Thinking XML: XML meets semantics, Part 2 covered initiatives for XML semantic transparency.
- This recent ebXML press release announced the completion of ebXML's 18-month initial development process.
- AIAG, GCI, OTA and HL7 are among the industry XML standards with whom the ebXML is collaborating.
- In this press release, RosettaNet announced a presentation giving their perspective on industry XML standards.
- Princeton's WordNet project spawned a lot of activity in the RDF community, including Sergey Melnik and Stefan Decker's RDF representation of WordNet and many other efforts as mentioned by Dan Brickley.
- Dr. Jonathan Borden has announced an online Wordnet browser using Dan Brickley's work.
- Alan Kotok's recent article on XML.com, ebXML: It Ain't Over 'til it's Over, discusses ebXML in light of its recent initial completion, and also touches on the future of ebXML.
- R. A. Smith of IBM Research touches on how ebXML fits into the fabric of e-business infrastructure.
- Check out IBM WebSphere Business Integrator, providing an integrated portfolio of offerings supported by a standards based service oriented infrastructure.
- Check out Thinking XML's previous columns.
Uche Ogbuji is a consultant and co-founder of Fourthought Inc., a software vendor and consultancy specializing in XML solutions for enterprise knowledge management applications. Fourthought develops 4Suite, an open-source platform for XML middleware. Mr. Ogbuji is a computer engineer and writer born in Nigeria, living and working in Boulder, Colorado, USA.