RDFa

Common Tag is an open tagging format defined using RDFa that makes content more discoverable. Unlike free-text tags, Common Tags are references to unique, well-defined concepts, complete with metadata and their own URLs.

The companies involved in the development of Common Tag are AdaptiveBlue, DERI (NUI Galway), Faviki, Freebase, Yahoo!, Zemanta, and Zigtag.

More information on the Common Tag Website.

Do you write HTML? You’ve just heard that Google now supports RDFa and you want to know where to start? Our own Steven Pemberton just published a fantastic RDFa introduction for HTML authors:

RDFa is a thin layer of markup you can add to your web pages that makes them understandable for machines as well as people. You could describe it as a CSS for meaning. By adding it, browsers, search engines, and other software can understand more about the pages, and in so doing offer more services or better results for the user. For instance, if a browser knows that a page is about an event such as a conference, it can offer to add it to your calendar, show it on a map, locate hotels or flights, or any number of other things.

Google just announced support for RDFa, starting with product reviews. Here’s Google’s FAQ on adding RDFa to your pages. This is a significant new direction for Google, where they will start looking at explicit data structure and provide enhanced search results accordingly. It’s fantastic to see them using RDFa for this task. It’s also fantastic to see them encouraging the use of a non-Google-branded vocabulary: open-vocabulary.org. Generic, reusable vocabularies built by industry groups, that’s exactly what we were hoping for with RDFa.

The side story here is that this was basically a Google-driven project from the start: they didn’t need the RDFa task force to create their vocabularies, to figure out how to mark up their pages, etc. Folks on the RDFa task force are finding out about this just now, as it happens. And we like it that way. RDFa is meant for communities of all sizes to mark up their pages, without centralized process overhead. Both Yahoo and Google’s RDFa launches were achieved without consultation with the RDFa community, and I consider that a success.

UPDATE: Google provides more details on RDFa for its rich snippets feature.

UPDATE 2: W3C blogs about the great news for structured web data.

Dan Connolly makes one of the more powerful arguments for truly web-extensible structured data in HTML, where you don’t need to ask for permission to innovate:

My view of Web architecture is shaped by episodes such as this one. While giga-scale deployment is always impressive and definitely something we should design for, small scale deployment is just as important. The Web spread, initially, not because of global phenomena such as Wikipedia and Facebook but because you didn’t need your manager’s permission to try it out; you didn’t even need a domain name; you could just run it on your LAN or even on just one machine with no server at all.

Over at WebBackplane, Mark Birbeck describes how the UK’s Central Office of Information has been generating RDF vocabularies via an open-source process, and then using those vocabularies to decorate their web pages. The blog demonstrates how they are being used to mark up job vacancies, and then how that information can be reliably scraped. Read more.

Another example of using the same jobs vocabulary is at Jobsgopublic.

Manuela Gastmeyer and Joachim Neubert of the German National Library of Economics (ZBW) announced:

STW Thesaurus for Economics is now available under http://zbw.eu/stw.

STW is a richly interconnected vocabulary in English and German on economics and business economics as well as some related subject areas. It includes subject categories and lots of synonyms in order to find the appropriate terms. Its publication aims at providing an interlinking hub for economics resources on the web of Linked Data.

The thesaurus is maintained by the German National Library of Economics (ZBW) and published under a Creative Commons (by-nc-sa) license.

It is delivered as XHTML+RDFa pages with an incremental search interface and a navigatable tree. A SKOS RDF/XML dump version can be downloaded, as well as a set of links to dbpedia concepts. More information about the design of the application can be found in a paper for the “Linked Data on the Web” workshop in Madrid.

Ben Adida points out in his posting Paris Hilton thinks RDFa is hot that MySpace has started using RDFa, and points to Paris Hilton’s page.

As Martin McEvoy has pointed out, Slideshare has started using RDFa.

Stephane Corlosquet has posted a video shown at DrupalCon this month demonstrating things you can do with RDFa and Drupal. Dries Buytaert (creator of Drupal) writes about it here.

In this post, Martin McEvoy announes a new extension for Dreamweaver supporting RDFa:

I am proud to announce RDFa Documents extension For Dreamweaver versions 8 to CS4

RDFa Documents contans a HTML TagLibrary with RDFa attributes and a XHTML+RDFa 1.0 Document Type Declaration.

The Extension will be available via Adobe Exchange (soon), after its passed a review by Adobe’s QA

The Extension Makes RDFa available to any Layout or Template that supports HTML/XHTML, It is also possible to convert existing Documents to RDFa using the Dreamweaver conversion utility.

For Now you can download the RDFa Dreamweaver Extension at the following location:

http://weborganics.co.uk/files/RDFa-Documents.mxp.

There is also a tutorial.