XHTML 2 is the Itanium of web technologies. You remember Intel and HP celebrating the Itanium architecture as the new super-duper technology, that should leave all RISC-based competitors in the dust. VLIW (re-branded as EPIC) was touted as a disruptive innovation. The future was Itanium.
But it was not! Forget the marketing speak from Intel and its only Itanium customer worthy of being mentioned, HP. Itanium has flopped. Yes, other RISC architectures, are struggling. MIPS no longer power high end servers from Silicon Graphics. SPARC is loosing market share. Only IBM Power PC seems to be holding its ground in the server space. But the x86 architecture, that was supposed to die, is reigning more dominantly than ever.
Backwards compatibility is everything
Being backwards compatible is not only a nice feature. It is a prerequisite that simply seems non negotiable. Let's look at a few successful products to get an idea.
Windows 95 and DOS-based games
Before Windows 95 all high end games were run from the DOS-prompt. Windows 3.x was only a nuisance for game developers. In order to achieve the highest possible speeds they often tweaked the hardware interaction in every possible way. Getting these games to run under Windows 95 proved a challenge, to say the least. Microsoft solved this by special-casing game after game. The operating system would recognize a particular piece of software, know that it required special handling and adjust accordingly. Even in ways that broke protocol.
When were punch cards invented? 1725. When did they become a big success? 1890. When did they become surpassed by other technologies. In the early 1960's. When did IBM drop support for punch cards from their operating systems? Not for another 30 years. I would not even be surprised if it was possible to attach a punch card reader to a brand new z-series computer today, and actually have it work.
XHTML 2 was Dead Pre Arrival
It did not die as a markup language for the web. It never lived. The day the decisions was made not to be backwards compatible, it was doomed. It never really mattered that it had every conceivable shiny new feature. Technical merits are simply not enough. Therefore it simply does not matter how much you shout about them, or how much you disdain the fact that HTML 5, due to its legacy, is
awful and badly designed.
Yes, I use PHP too, and no matter how much one shouts the relative technical merits of Ruby or Python, PHP seems not to grow weaker. Ugliness just is not that big a factor. A strong user base, re-use of code and know-how, ability to find advice and support, such things matter. Sociology always trump technology.
The future for XHTML 2
I have friends who prefer XHTML 2 to DocBook, for data storage on the server. Reading Steve Pembertons thoughts about the future, he seems to believe that is a viable niche and that it can make a comeback that way. And why not, in a controlled environment the improved semantics of XHTML 2 over legacy HTML may provide significant benefits. Pushing XHTML 2 as a progressive enhancement, server side, might work.
Encouraged by none other than Ian Hickson himself XHTML 2 will continue to be developed in a working group outside of the W3C. Can it make a comeback? Once upon a time the W3C decided to axe HTML. Many developers, myself included, thought it was the end of HTML. I was wrong. I therefore will not say, good bye XHTML 2, but a revoir.