Lessons learned from the XML experiment

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

XML has been a grand experiment.

Shall we summarize what we've learned?

I see two defining lessons:

1. Data is a first class entity: XML showed the programming world (and the rest of the world) that data is not just confined to the bytes exchanged in subroutine calls, but data is a serious issue, worthy of investing time and money in defining and validating collections of data for exchange.

2. Design for the masses; once the cat is out of the bag, you can't put it back: XML was created for use by the entire world. A technology that is targeted for use by the entire world must be understood by the entire world, which means that it has to be very simple. The XML creators thought they had created a sufficiently simple technology, but they didn't go far enough in simplifying. Since the release of XML in 1998 there have been numerous attempts to create a simpler version, but those attempts, noble as they were, have failed to get any significant uptake by the world-wide community. Lesson learned: when creating a new technology, make it as simple as you possibly can, then simplify it ten-fold. Once you've released your technology onto the web, you won't be able to take it back and simplify it. Instead, someone else will come along and provide something simpler and the world will adopt it, not yours.

Do you agree with these lessons learned? What other lessons do you take from the grand XML experiment?

/Roger