One of the most interesting hallway conversations that I had at Balisage was with Eliot Kimber. He and I spent about two hours exploring the differences and similarities between DocBook and DITA.
Here's my synthesis of Eliot's position:
The only difference between DITA and DocBook is specialization, and specialization is why DITA is better.
I'll accept the first part of that observation without argument. To ordinary mortals, DITA and DocBook might look very different, but Eliot is as skilled a markup wrangler as you're likely to encounter. Assuming you worked out a mapping for whatever semantic ambiguity there might be in your corpus, given time and inclination, I'll grant that Eliot could convert anything into anything else. So in that broad sense, they're the same.
That just leaves specialization. I've historically not been impressed by specialization. But I've been wrong before.
In talking to Eliot and thinking about it afterwards, I've come to realize that I'm burdened by a particular set of assumptions, formed long ago, that may no longer usefully guide me through the real world.
One of the critical, motivating goals for adopting an XML (or SGML) publishing system in techpubs was the ability, when all was said and done, to demonstrate a lights-out, high quality, print publication system. You poured valid documents in at the top and aesthetically pleasing, professionally typeset pages that adhered strictly to the organization's design and style guidelines came out the other end.
The way, the only way, that this was achieved was to start with quality tools (editors, formatters, typesetters) and customize each of them, perhaps significantly, until all the stake holders signed off that the results were up to the required standards of information content, layout, design, and typography.
That was then. This is now?
Lights-out publishing is still a requirement for some organizations, especially in core techpubs, but I think there's also evidence that tools like Adobe InDesign have relaxed this requirement for many more organizations. If you're going to pour the markup I send you through a visual tool and make even a light manual pass over the document, you can afford to be a lot more forgiving about the markup I send you. And a system that is “a little bit forgiving” is vastly, spectacularly easier to implement than one that is “not forgiving at all”.
If the web has taught us anything, it's that quality hardly matters at all. Sturgeon's Law applies. We now routinely accept layouts that no self-respecting publisher would have had the temerity to propose years ago.
And finally, this printing ink on dead trees at a thousand-plus DPI, who does that? It's a rare piece of software or hardware that comes with more than a pamphlet these days. Environmentally, that's probably a good thing, but it has done nothing to improve the quality (see previous point) of what's produced.
How is this related to specialization? It's related to specialization because specialization is about interchange. DocBook has always been about interchange: precise, carefully managed interchange.
Specialization is about blind interchange: I send you my documents, documents that contain markup you've never seen before, you run them through your normal toolchain, and the results are “good enough”.
If you're carrying around the assumptions I outline above, blind interchange is a manifestly absurd notion. But if you relax your assumptions to perhaps more accuratly reflect the twenty-first century, then maybe blind interchange becomes not just possible, but practical.
And maybe, just maybe, that makes specialization intersting.
Don't pay any attention to those creaking, scraping noises that you hear. That's just me rearranging my mental furniture. More to follow.