The XML-DEV discussion list - the open, unmoderated list supporting XML implementation and development and managed by OASIS - recently considered the burning question of whether XML is complete...or is still missing something.

Renowned XML expert Simon St. Laurent, who initiated the discussion, commented in his opening remarks that, looking at the three original aspects of XML - which he defines as syntax, linking, and styling - it looked to him like they may be close to done. "There is ongoing work on XML," he wrote, "but I think it's fair to characterize both XML 1.1 and Namespaces in XML 1.1 primarily as efforts to clean up outstanding issues (Unicode tracking, excess namespace declarations) while possibly sliding something new in (NEL, IRIs) rather than any kind of new structure or significant modification."

As for XML Schema, St. Laurent, who is author of books like XML Elements of Style, XML: A Primer, and Inside XML DTDs, noted that - so far as he could tell, anyway - the topic had exhausted its participants and he hadn't heard much talk on that front. "Critics seem to have moved elsewhere," St. Laurent opined, "and while supporters occasionally talk about trimming it, there's not much activity there."

What about XLink and XPointer? "XLink is finished, though hardly anyone uses it," continued St. Laurent, "and XPointer is apparently in a dash to the finish before the Working Group (WG) expires on 31 December. Whether XPointer will find more use than XLink thus far remains to be seen."

That left XSLT. "XSLT is certainly growing in its 2.0 development process," was St. Laurent's view, "but it's far from clear that there's strong community support for more than a few pieces of it. XSLT could use a cleanup/minor addition process, but that doesn't seem particularly likely to happen, at least given current World Wide Web Consortium (W3C) activity."

St. Laurent concluded with a couple of open questions: "Are there more issues like Character Entities waiting to surface? Or (apart from that issue) can XML declare victory and call itself complete?"

Not surprisingly, given that XML-DEV has been the premier XML discussion list in the world since its creation in January 1997 by two UK-based professors, Peter Murray-Rust of the University of Nottingham and Henry Rzepa of Imperial College, there were plenty of dissenters once St. Laurent had expressed his viewpoints.

Andrew Watt, for example, joined the discussion to say that, so far as he could see, "We are moving to an XML world with approximately two data models: 1) DOM in the browser for SVG, XHTML, etc., and 2) XQuery/XPath/XSLT/Infoset/AABSABI for the rest." He wondered if that was how others saw things. Watt also noted that, as he put it, "There is a ton of work ongoing on XQuery (and therefore also on XSLT 2.0 and XPath 2.0). And, if my guess is correct, they will pretty much go straight on to add update functionality to XQuery."

St. Laurent was not impressed. "XQuery is a toolkit for working with XML, not part of XML itself," he replied, adding: "The same can be said of XSLT, though XSLT was pretty clearly part of the original style project."

Naturally enough, given the nature of the question ("Is XML Complete?"), the issue of whether XML 2.0 is on its way was raised. Richard Tobin chimed in to say that he wasn't aware of there having been any serious study on this question yet.

"I have heard a vast range of views on what XML 2.0 should be if there is one," Tobin wrote, "from a unification of XML 1.x + Namespaces + Infoset + no substantive changes, to a completely redesigned language."

Douglas Husemann offered his thoughts on XML 2.0 as follows: "Yes an implementation that takes Namespaces into account from the very beginning would be a good thing...but perhaps standardization on specific standards for infosets would be a good thing also," he added. "It would be easier for generated languages to work together in a future implementation."

Let us give the last word to Simon St. Laurent himself, since it was he who started the whole discussion: "I expect XML applications will go on for another decade or more regardless of whether there's any change in the XML core," he declared. Or, in other words: yes, XML is - give or take - complete.

Activities like the recent XML Security specs are largely, in St. Laurent's view, just an adaptation of existing security specs to XML structures. That's to say, it's just an XML application rather than a change in the XML core.

"It's (often) good stuff, and it's interesting," St. Laurent concluded, "but it's about using the infrastructure XML provides rather than building the XML infrastructure."