I have read a few introductory books on XML and dabbled with XSLT for a long time, for me an XML document is a tree of nodes that I can navigate via XPath, or which can be parsed and turned into a stream of events. XML Technologies are built on top of either of these two powerful approaches.
My interpretation of what I obtain at the end of such an XPath, or with such a generated event is a different issue, though obviously of major importance too.
I have been interested for some years in the idea of an XML
technologies based infrastructure that is very cost-efficient for data
management in science. For me Hans-Juergen's papers at Balisage have expressed very
well this general idea and a detailed analysis of what might be done to
further it.
However. in the IT circles I've move in there has been a major 'perspective' related barrier to achieving anything significant towards this vision,
which is the OO programmers 'every thing is an object' perspective vs the XML 'every thing is parseable and navigable data' perspective. There is a related difference of perspective in the database world between the set (relation) and the navigable graph based approaches it seems.
I think that the
recent posts by Kurt Cagle on the ACA implementation problems and his
diagnosis of the causes have implicated this contrasting perspective, hence its importance as a topic for discussion [The OO perpective leading to the notion that objects can massage any parsed data into something useful, well possibly yes, but at what cost?]
I think that such differences in perspective relate very much to
tools (technologies), the tendancy for all of use to like/want/need to
use the tools that we are familar with and as a result not question the
assumptions on which the tools are based (If all you have is a hammer,
everything looks like a nail), or, to be that interested in learning about alternative tools in any great depth, particularly when your boss is asking for a time estimate for task completion.
Hans-Juergen seems to me to be mainly interested to tease appart this specific difference of perspective and I admire his efforts in this.
Now. in his efforts there might be a deeper truth about markup missed (in a 'technological rush' maybe? ;) ), one that I too have missed and which I am happy to learn more of. But I am VERY interested to focus in on the ACA issue and what lessons the "XML Experiment" might hold, given that my analysis of its origin is valid.