I was reading Elliotte Rusty Harold's predictions for the XML world in 2007 and spotted this (which Danny has also pointed out):
2007 is the make-or-break year for the Semantic Web. The specs are done. The tools are in place, and there's still not a whiff of a killer app anywhere to be seen. The Achilles heel of the Semantic Web may well be the complete disinterest of most authors in producing anything remotely approximating metadata for their pages. Search engines have learned to ignore any user-created metadata because honest publishers don't bother with it and dishonest spammers abuse it. Screen readers don't even bother with the limited semantics already in HTML, trying instead to figure out what the page looks like.
Is it really make or break for the Semantic Web? Elliotte goes on to say some nice things about GRDDL which I do agree with. But the contention that this is the Semantic Web's last chance doesn't riff with me. Technology, especially standards track work, takes years to cross the chasm from early adopters (the technology enthusiasts and visionaries) to the early majority (the pragmatists). And when I say years, I mean years. Take CSS for example. I'd characterise CSS as having crossed the chasm and it's being used by the early majority and making inroads into the late majority. I don't think anyone would seriously argue that CSS is not here to stay.
According to this semi-official history of CSS the first proposal was in 1994, about 13 years ago. The first version that was recognisably the CSS we use today was CSS1, issued by the W3C in December 1996. This was followed by CSS2 in 1998, the year that also saw the founding of the Web Standards Project. CSS 2.1 is still under development, along with portions of CSS3.
Let's compare that with the key Semantic Web specifications: RDF and OWL. RDF emerged from earlier work by Guha called MCF and, with a heavy dose of XML courtesy of Tim Bray, it was issued as a recommendation by the W3C in February 1999. It was followed almost exactly 5 years later by a set of cleaner specifications that tidied up some loose ends and removed some cruft from the earlier specification. The OWL recommendations were issued at about the same time.
So why did CSS take so long to gain traction? 13 years from inception, 10/11 years from first accepted specification? To be honest it didn't really solve a new problem. For most people it just solved a problem with an existing solution in a new way. HTML already allowed people to style their pages, to align elements and to layout their documents. It did it rather well for most people and for those who thought in terms of a few HTML pages CSS just seemed like a new way to do the same old thing. However, for those who needed to apply consistent formatting across a very large number of pages; or for those who wanted to be able to offer different styles for different users or media; or for those who wanted to share their designs then CSS was the clear winner.
However, if it were not for the efforts of the WaSP raising awareness of the benefits of CSS, we'd probably still be in <FONT> hell. Who can say they haven't cursed at the "CSS Tax" of hacks and workarounds or shouted in anger when trying to achieve simple effects such as consistent font sizes or sidebars that extend to the bottom of the page. It took the patient evangelism by WaSP 9 years for us to be able to say confidently that CSS has crossed the chasm.
There are some strong analogies with the Semantic Web here. Like CSS, to most people RDF seems to offer nothing but a new way to solve an old problem. However, for those that have needs beyond a single document or a single data silo, RDF offers something genuinely different. Sharing data, combining data from different sources, evolving schemas - all these things are strengths of the RDF model and it's only now that people are seeking to break down the walls and share data at Web scale.
So is this the year of make or break? Hardly! We could do a gross comparison with CSS and equate CSS1 (1996) with the first RDF recommendation (1999). That suggests there's another 3 years before we can expect the Semantic Web to cross the chasm. However, I think the real comparison has to take into account the evangelism and activism around the technology. It's taken 9 years of WaSP cajoling vendors and pestering designers to get CSS to where it is today. The analogue here is SWEO the new Semantic Web Education and Outreach group. This group (I'm a lurking member) has only just started the battle that took WaSP 9 years to win!
I'm hoping that the time frame for the Semantic Web crossing the chasm is somewhere between the two estimates; between 3 and 9 years. I'm hoping that it's going to be at the lower end of that scale, say 5 years, but that still means we have a long multi-year struggle to evangelise and persuade. It's going to be worth it!