Raw

In comments on a post on G+ I said something I might regret:

"There are plenty of RDF-based applications around, but none really have much broad public appeal."

Ade Oshineye responded with "why do you think that is?"

Ok, overnight I remembered there's at least one app (or set of apps if you prefer) that uses RDF and has a lot of adoption: Drupal. According to Wikipedia it's used on at least 1.5% of Web sites worldwide, and has RDF in its core. Then there's data.gov.uk, a public-facing national government site that's RDF through-and-through. I'm a little out of touch, there are no doubt quite a few other good examples of where I'm wrong.

But given that RDF has been around for 5 years*, it's the way of doing data on the Web and virtually every Web-oriented app uses data somewhere, why isn't it ubiquitous?

(* solid specs came out in 2004 although SPARQL wasn't until 2008 so I'm splitting the difference for a rough date for when it became usable)

RDF isn't something that's going to be in your face anyway, so "broad public appeal" is slightly off-target. Developer adoption may be a better key. Whadever.

In terms of it as a database tech, compared to relational DBs (MySQL etc), custom data handling (Twitter uses Ruby message queues), novel DBs (Facebook uses a key-value store Cassandra apparently) RDF stores don't get much of a look-in. Ok, arguably the big scale things need to be custom to hone performance, but why, alongside the Big Data handling, don't we see RDF augmentation?

For consuming apps and desktop apps, I can't actually think of any well-known ones off the top of my head (I think quite a few of the music apps on Linux use librdf under the covers). I don't have a mobile device - any iPhone apps?

What I find a little bizarre (and please give me counter-examples), is that in the areas where RDF really shines - Web-oriented data integration and reuse - there are hardly any well-known apps out there at all, using any technology. There are a handful of feed aggregators and things like techmeme, but the level of integration there is pretty trivial. (Before Kingsley jumps down my throat - OpenLink Virtuoso is seriously good at this kind of stuff out of the box - but what I'm after is where these things are being used by twitter-sized demographics).

There's certainly something to what Lee Feigenbaum said the other day, the wrong question is usually asked, it should be: What can I do with Semantic Web technologies that I wouldn't do otherwise?

In terms of app-building, right now most parts of most things can be built relatively easily using other technologies, so unless the RDF stack is part of the developer's on-hand toolkit (like e.g. LAMP) it won't be first choice. I do suspect that while the false perception that RDF is complex per se isn't so prevalent these days, there's still a notion around that RDF is complex for the benefits it offers. i.e. linked data isn't perceived as a significant value-add, so why bother? The primary objectives can be acheived by pushing around little JSON objects ("jobbies"?) in a fairly arbitrary fashion, so why look further? But data on the Web surely isn't a niche thing...

Feel free to shoot me down in flames from all angles over this one (I'm not interested in advocacy here so don't care if I expose the wrong message) - I also suspect there's still something in the idea that people simply don't get it. While developers seem to have no problem representing pretty much anything in local databases, the idea that anything can be represented on the Web in a similar way hasn't been grasped. I reckon there's good evidence in virtually every high-profile project. Things tends to be focused on HTML (with a little Javascript) and the browser experience. For service-oriented systems the unwritten assumption is that the services will tie into the same view. I'm certainly not saying that this focus is wrong (those user-facing components are vital), just that it can lead to a blinkered view of what is possible. Only relatively recently have developers at large started looking at things like the identity of people on the Web. You still don't see the same attention given to everything else in the world - products, ideas, activities. Ok, you might point to activity streams and the like, but the subject of those activities still largely tends to be doc-oriented: messages or posts. You might point to schema.org and microdata as ways in which people in the Web development community can put data on the Web. But scratch the surface and the main goals underneath are things like SEO, most of the data being expressed is document metadata, not data about the real world. (Next time you go shopping, notice your interactions with the world from finding your car keys onwards, compare and contrast with the Amazon experience.)

The other day I posted a question on G+ that probably should have gone here: All the necessary components were in place for online social networks, in a distributed form, before Facebook & co. came along: blogs, aggregators, the various protocols. So why were Facebook & co. so successful? (got some good comments there, and was very pleased to find out Andreas Kuckartz is researching the question)

The question of data on the Web seems to lie in a similar socio-politico-technical morass. On federation, I'm afraid I'm inclined to agree with Eric Siegel : "I predict decentralization is inevitable, but its very very far away." I feel pretty much the same about the Web of data, though perhaps not so far away (unless I'm confusing small and far away :)

[ooh - a good point on that from Seb Paquet I'd missed before: The folks who grokked decentralization didn't master social experience design and UI design as well as Zuck, and decentralized infrastructure is harder to monetize so getting funding was difficult.]

One final question dedicated to folks on Planet RDF, from danbri in response to (the Facebook re-presentation of) my post yesterday:

If RDF is so great, we should all be rich by now? :)

Another quote, it must have some relevance - via the BBC, from Sir William Preece chief engineer of the British Post Office in 1876: "The Americans have need of the telephone, but we do not. We have plenty of messenger boys."

Still no system here yet, comments to G+ again.