You will no doubt have noticed that in recent times, the letter "X" has been co-opted by the XML world. There was a time, not too long ago, when "X" typically denoted a completely different technology space known as X11.
X11 is a software technology for running graphical user interfaces across networks. It brings back memories for me, some fond, some not so fond. I first programmed X11, would you believe, on an Intel based Sun machine known as the Sun 386i while working in London in the late Eighties. A few salient points about X11.
1) X11 is really quite an old, mature technology that has not exploded onto the scene yet. However, it is quietly working away, most notably on Linux and gaining ground all the time.
2) X11 is a very, very large system. I remember the first ever O'Reilly books I bought were three big thick X11 books. They just covered the core libraries!
3) X11 takes a very odd, but very interesting approach to graphical user interfaces. Somewhere in between a browser and thick client.
Add these facts together with the current crossroads in web browser technology and I think something interesting might be portended.
It seems we have reached something of a crossroads in network (web) GUI technology. Some would argue that the browser is giving way to richer 'thicker' applications communicating with servers over web services. Mind you, some would argue that the browser has only started to evolve.
X11 fans would probably argue that the X system provides an interesting alternative model to the markup-based browser. A model which allows very rich GUIs without, as it were, 'thickening' the client into something non-generic.
Maybe the thought I am about to express is old news. If so, I have not found it on the Web anywhere. The thought is this: what if we created a stripped down version of X11 specifically for Web use? Could we create an interesting hybrid browsing client supporting rich user interfaces?
I think the answer to that is probably yes, and I like the possible parallels with what happened to SGML in the late Nineties. SGML was a large but powerful system with over a decade of accumulated knowledge by then. It got distilled down into a simpler, leaner core, re-branded and launched as a "new" technology - XML.
Could the same thing happen to X?
I think so.