Re: [xml-dev] How long before services sending/receiving XML mightneed r

[Michael Kay <mike@saxonica.com>]

>Such changes to the driving forces must inevitably lead to technological changes at some point. 

The more widely used a data interchange standard is, the more resilient it is. 

Genealogy data is still exchanged in GEDCOM format, as it has been since the 1970s (it was at version 5.5.1 for twenty years, and has recently been revised to 5.5.5, largely to change the character encoding from ANSEL to Unicode). There are plenty of other examples of interchange standards in widespread use that predate XML. I think someone mentioned MIDI as another example. Once these standards are incorporated into enough different applications, the cost of change invariably exceeds the benefits. And attempts to replace them often fail dismally. The same considerations apply to standards built on XML: if they are in active use, they will endure. So there's absolutely no reason to doubt that there will still be plenty of XML around in 100 years time. And if there is XML around, there will be XML technology around to process it, because the data represents a much larger investment than the software.

Of course new things will come along: all standards can be improved, especially if you focus on particular areas of application that the old standard wasn't optimized for. But the question starting this thread was whether and when services using XML might need replacement because XML technology or skills are longer available, and I think the answer to that is never. We're still using Unix APIs designed 50 years ago that everyone knows can be improved upon; we're still using SQL, which is equally ancient and crumbly: key interfaces like that, which are essential to interoperability of complex IT systems, don't wither and die however antiquated they become. No-one can afford the cost.

Michael Kay
Saxonica