As Danny reported, it seems that Joost has triggered a race for using RDF in video metadata: ZDNet has reviewed the alpha version of Seesmic, an online video applications using RDF “as the foundation”, supporting vocabularies such as FOAF, SIOC, DC, MPEG-7 (cf. Multimedia Vocabularies on the Semantic Web report for further details). As an aside: Seesmic supports RDFa!
Fresh from the Semantic Web Activity News: GRDDL is a W3C Recommendation.
As you might know, GRDDL can also be used to generate RDF from XHTML+RDFa documents. However, there are people around preferring to use RDFa rather directly 
Ivan Herman has announced a new Python-based RDFa implementation in his blog. The Python package is available online.
Ivan has also interfaced it to a Web page that takes the URL of an RDFa page and extracts the RDF in a choice of outputs.
Gauthier Poupeau continues his work on exploring what one can do with Operator and RDFa. He now has an Operator action script that look for ISBN numbers expressed as RDFa, then links them to Amazon. He has another Operator action script that gives you a URL’s history at delicious. It’s all described in detail in French on his blog.
All of these small client-side hacks are the beginning of the most important part of the whole semantic web story: giving the user power to do things according to the semantic markup. There’s so much promise here, it’s exciting to see RDFa providing a solid basis for this kind of innovation.
We started to gather applications on the Web that utilise RDFa. Have a look at the RDFa in the wild page and do not hesitate do contact us if you encounter a new Semantic Web application that uses RDFa (or maybe you want to announce your own?)
Thanks to Mike Kaply Operator 0.8 is now available. Operator is a Firefox plugin supporting all kinds of metadata in HTML (microformats, eRDF, RDFa). Try it out !
So, after some beta-testing, the W3C Markup Validation Service is now available in a stable version. This validator checks the markup validity of Web documents in HTML, XHTML, SMIL, MathML, and: XHTML+RDFa … try it out!
In case you successfully pass the validation, you’ll be rewarded with an icon stating that you have produced valid XHTML + RDFa.
You can then choose between two versions:
or
PS: In case you need some material to play around, have a look at the RDFa Test Case repository.
As Ivan points out, Triplr now supports RDFa:
I can now use the URI http://triplr.org/rdfa-rdf/http://rdfa.info/ to extract or refer to the RDF content from the RDFa info page’s RDFa statements. Of course (after all, this is Dave’s tool!) I could also put “turtle” in the URI instead of “rdf” to yield, well, turtle.
What can I say…this post has everything.
First, it shows how Egon has used RDFa to mark-up HTML documents with information about molecules–something he started doing last year. But then it shows how he uses the latest version of Operator (0.8) to parse the RDFa, and generate menus which will search chemistry databases.
What’s most interesting about this post for me, is that Egon actually went through the process of doing all of this by using a GreaseMonkey script first, before he then used Operator to do the heavy lifting. GreaseMonkey is great for general purpose processing on a page, but the important thing about extensions like Operator is that they deal with your page at the semantic level. It then makes it very easy to do the type of thing that Egon has done, and add a menu item that searches a specific database. By talking us through the ‘long-hand’ technique we start to see the real benefits of Operator.
I’m looking forward to the next instalment, because I think Egon’s on a roll here!
The Simile project at MIT has been developing fantastic tools to let you manage interoperable data on the web without a backend database. In particular, David Huynh’s Exhibit project lets you present structured data in a beautiful, dynamic, JavaScript-driven way, again without a backend database (see their US Presidents example).
One issue Exhibit has been struggling with is that, if the data is in JavaScript, and it isn’t rendered in HTML until the JavaScript takes over, search engines may not be able to index the content. As of version 2.0, thanks to Keith Alexander, Exhibit will support an RDFa importer: the data can be expressed in simple HTML with RDFa, and the Exhibit code will replace this basic HTML with the more dynamic, navigable version. Yet the search engines will still be able to see the full content, without having to type anything in twice. That’s the power of interoperable data in HTML: all tools that currently depend on HTML still work, while tools that require greater structure are built without repeating the underlying data.