Gartner Group developed a concept called the "Hype Cycle" to show common patterns of technology adoption. The cycle starts with manic enthusiasm followed by a depressive plunge into self-doubt, then cautious use, and finally, steady-state mainstream adoption. Sometimes this model seems like a force-fitting of trends to reality, but it decisively applies to content-centric XML. Note that I didn't say XML-based Web applications, which leaped from the peak of enthusiasm, bypassed the trough of despair, and went directly to adoption. I am one of many, however, who rode the XML content roller coaster up: high hopes for the use of SMIL in multimedia; SVG for graphics; create-once and reuse many times for everything from office documents to highly-disciplined technical documentation. And down: Microsoft ignored SMIL and SVG; few office workers ever mastered using MS Word styles that could provide additional document structure. What hope was there for the discipline and promise of XML?
After attending the XML 2004 Conference, I see real evidence that mainstream adoption is occurring, even if invisibly. XML adoption has been building for several years, but without the fanfare of its Web application sibling and prerequisite. Content is king, but shaking off the inertia of centuries of publishing tradition to leverage XML's promise has taken longer than I expected.
The conference exhibits showed some truly innovative product directions. A Japanese company called Justsystem Corporation announced a technology framework for using any combination of XML models, with two-way connections between user and content (product announcements expected summer 2005). Other smaller offerings like Wolfram's Publicon promises math publishing at a shrink-wrap price.
Still, all conferences have interesting exhibits, but is anybody really creating XML content, apart math publishers or verticals like airlines, government agencies, and automobile and airframe manufacturers? Are non-specialists consuming XML content except as RSS feeds? A better way to pose that question is: "Has content-centric XML made its way to non-technical users?" The simple answer is "yes," even though—or especially because—mainstream adopters are increasingly unaware that they are using XML. After nearly an hour interviewing Jean Paoli, senior director of XML Architecture for Microsoft, it is clear he believes that XML has gone mainstream. He cites many examples as proof: North Carolina police officers report incidents from the street on mobile data terminals; nurses in New York-Presbyterian Hospital use InfoPath applications that create and customize patient information for physicians; Continental Airlines exports information from reservation systems to an air status spreadsheet for airline cooks using Office to prepare airline meals; the Danish government saves Word documents as XML a year after Microsoft announced a royalty-free licensing program for its Microsoft Office 2003 XML Reference Schemas. This license allows archiving Word documents in a vendor-independent format, required by some countries. Paoli's observation: "Nurses, cooks, and police don't know nor care about XML. People won't become literate in XML. End users will create what they think about as documents, but the document becomes more intelligent."
Another front-runner in the mainstreaming of XML is Adobe; its leveraging of XML in its new Acrobat 7 release is both broad and deep. One surprise was its bundling of Forms Designer with Acrobat Professional. Traditional forms designers, XML engineers, and even business people using an interactive wizard can create and deploy sophisticated forms using whatever XML schema they choose. You can save the completed forms data as XML and aggregate it into an Excel spreadsheet using just Acrobat. Best of all, whether the result is an IRS tax form or a simple template to capture court records, the author is completely unaware that he or she is creating XML content. Moreover, interaction with XML forms is all local on the PC, saving time (and server load)—another invisible benefit envisioned by XML.
Perhaps there's even a place for interactive SVG presentations (life after PowerPoint). At the show, Wendell Piez of Mulberry Technologies demonstrated the possibilities. Justsystem's technology may provide practical products for interacting with XML SVG data for users who don't know a JPG from an SVG.
Mainstream XML is happening as we learn to make it transparent. Success means enabling authors to manage content without being aware of XML, just as they may drive their cars unaware of the 30 or so microchips under the hood.