[11 February 2008]
The XML spec became a W3C Recommendation ten years ago this week.
Tim Bray has posted some character sketches from the period; Eve Maler has followed suit with some recollections (and an online version of Maler/El Andaloussi! Woo hoo!); this has inspired me to think about doing the same. What follows is the first in (what I hope will be) a series of moments I remember from the creation of XML.
If you look, you can find a lot of stories about the beginning of XML. It surprised me, at first, that they all seem to be different; it surprised me even more to find some told in the first person by people whom I had not suspected of being involved with XML at all. But I shouldn’t have been surprised. Scores or hundreds of people were involved in the development of XML, thousands in its spread and uptake. In some sense, then, XML will have had scores, or hundreds, or thousands of beginnings. Why should I think I know about them all? Questions like “How did X start?” often mean not “How did X start?” but “How did you come to be involved in X?” — or, at least, that’s how we answer them. The beginnings of XML? I don’t know. But I’ll tell you what I do know; I know when I first heard about it.
The second WWW conference was in Chicago, in October 1994. With Bob Goldstein, one of my colleagues at the University of Illinois at Chicago computer center, I had submitted a paper on how the Web would achieve its true potential only once it had SGML awareness (“HTML to the Max”). We had to do it for the conference in Chicago, because the computer center would certainly not have paid for travel to go anywhere else; they weren’t happy at being asked to pay the registration fee, let alone travel.
This was the conference at which I saw SoftQuad Panorama for the first time, but I could not figure out the stylesheet mechanism well enough to use it to deliver my slides; later I did, and used Panorama for slides for years after that.
Sometime during the conference I ran into Jon Bosak, whom I knew from SGML conferences, and Dave Hollander, whom I may have been meeting for the first time. Jon was at Novell, Dave was at HP (where I believe he was in charge of building hp.com), and the conference hotel (as I remember it, the Hilton on Michigan Avenue it) was hopelessly overcrowded; there was no chance of finding a place to sit and have a cup of coffee.
Fortunately, I was local, and knew the neighborhood slightly, so I led Jon and Dave up the street a bit to the Cafe des Artistes, where we sat on the sidewalk in the October sun and talked about markup and the Web. Browser makers didn’t want to support SGML; they thought it was too complicated and would make the browsers heavy-weight. This seemed like an excuse to me: browsers were already putting on more weight than SGML support would have required. We speculated about defining a simpler profile of SGML, so they couldn’t use complexity as an excuse. Where? The ISO working group was not going much of anywhere with the five-year review and revision of the spec; it seemed unlikely anyone would get any joy there. SGML Open? Somewhere else? Jon had an idea it might fly as an idea for a working group at the new World Wide Web Consortium. Dave thought that SGML support would be the best thing, but if we couldn’t persuade people to do that, he had a fallback idea. HTML appeared hopelessly unequal to the task of publishing serious technical documentation, but Dave’s experience developing the Semantic Delivery Language (SDL) had persuaded him that you could have a reasonably small markup language with some hooks for richer semantics. SDL had been developed for help systems and delivery on CD-ROMs, and in it each element carried an attribute that said what kind of element it had come from in the SGML vocabulary in which the document had been prepared. (Nowadays you’d do that with the HTML class element.)
[Googling for “semantic delivery language” just now, I find that about that time Jon put together a proposal for specifying a Hypertext Delivery Language (HDL) based on SDL and optimized for WWW delivery; the copy on the W3C site says it was last modified 1 November 1994, less than a month after the Web conference.]
Other people had specified subsets of SGML before; I had done one myself in 1992 (“Poor-Folks SGML”), and several others were also used as input to the design of XML. And of course I had just given a paper urging that Web software start supporting SGML.
But I think of that cup of coffee at the Cafe des Artistes on Michigan Avenue as the first time I heard anyone talking about the specific idea that became XML.
And you, dear reader? What are your recollections of the beginnings of XML? When did you start thinking about the ideas that became XML? When did you first encounter the effort that in the end produced the spec? Tell me here, or write about it on your own blog.