• geolocation of microblog messages (see example below), which shows one more benefit of the LOD cloud, as coordinates of posts are provided thanks to the GeoNames integration and OPO;
• ability to delete messages (deletion being then propagated to other hubs using SPARQL/Update) and to automatically purge messages older than X days (mainly to keep the DB lightweight - starred messages are not removed);
• on-demand creation of FOAF profile, in case one wants to try SMOB but does not have one (or does not want to provide it);
• parser for hyerlinks in microblog posts; and
• updated installer, allowing to select if SMOB should be used as a Twitter client (read / write settings).

BTW, as for the previous updates, you have to remove your config file and re-do the install procedure, and it will not remove your existing messages.

In addition, the new release provides:

• RSS feed for hub owner's messages;
• Automatic @reply when replying to a Twitter message (including sioc:addressed_to annotation);
• Updated user-interface for #tags mappings, now done using tabs to avoid too much scrolling;
• Ability to directly check @reply messages;
• Starring system using the Review vocabulary.

SMOB v2.1 can be downloaded here. If you used a previous version, you will also need to apply this patch after the update. It may remove some of your following / followers (as there have been some changes in the related RDF data - this should be taken into account by the patch, but who knows ...), in that case you'll add to add them again, sorry for the inconvenience !

Hopefully, a 2.2 release will be out in the next weeks, including geolocation of messages, advanced browsing features and other funky improvements. Feature requests can also be suggested on its dedicated bugtracker.

So, I recently worked deeper on the use of Linked Data for music recommendations and I'm happy to announce dbrec, a service providing recommendations for the 39,000+ artists available in the DBpedia dataset (i.e. identified as instances of dbpedia-owl:MusicalArtist or dbpedia-owl:Band). The recommendations are computed using an algorithm for Linked Data Semantic Distance and take into account the various links that connect two resources, either directly (e.g. artists having played together) or indirectly (e.g. being on the same label or having covered the same song). Moreover, dbrec, explains the recommendations to the user, by keeping in mind the various links that have been used to compute the recommendations. For instance, the following screenshot shows why Big Brother and the Holding Company is suggested for a search on Janis Joplin.

dbrec is fully based on Semantic Web and Linked Data technologies and, in addition, exposes all the recommendations publicly (under a Creative Commons license) in RDFa using the dedicated LDSD ontology. For more details, you can check the homepage of the service, and start exploring the recommendations. Hey ! Ho ! Let's Go !

While we did not improve is much since then, there have been a lot of work on it these last months (about 250 SVN commits since end of October, when we decided to revive it) and I'm happy to announce that SMOB v2.0 is now officilay out, after some internal beta-testing during the last weeks.

Overall, it has been a complete code rewriting and architecture redesign since the previous release. While the initial version relied on clients and servers to respectively publish and aggregate data, this new version is based on the concept of distributed and independent hubs that communicate each other to exchange data, being microblog posts as well as followers / following lists.

As you can guess, SMOB is entirely based on Semantic Web and Linked Data technologies. Then, each hub locally stores its data as native RDF (using ARC2, also providing a SPARQL endpoint per hub) and the communication between hubs is provided via SPARQL/Update over HTTP. In addition, each hub provides RDFa information about itself and the microblog posts it contains, using SIOC, FOAF and OPO as well as interlinking with the Linking Open Data cloud using MOAT and CommonTag. Regarding that later aspect, the UI has also been improved and the system now suggest URIs from DBpedia and Sindice (new wrappers can easily be added) as soon as you use any #tag when writing your posts, and the mappings between tags and URIs are remembered for further usage in other posts. Finally, new content is posted to Sindice to enable discovering and querying microblog posts across the (Semantic) Web.

For those who want to get a preview before installing their own hub, here are two screenshots of the interface, the first one about publishing data, where you can see #tag mappings, as well as broadcasting to Twitter.

And in that second one, you can see a list of posts, with links to RDF data, hashtags mapped to URIs, etc.

You can also have a look at my SMOB hub here.

SMOB v2.0 is available through its download page and is licensed under the terms of the GNU GPL as its previous release. In addition, we are happy to provide commercial support for it, such as development of new features or custom integration of SMOB for enterprise microblogging purposes. For any enquiry about these commercial services, simply send an e-mail to at alexandre.passant[AT]deri.org, indicating [SMOB Support] in the subject line.

Oh, and finally, SMOB graduated and now got its own domain at http://smob.me. Enjoy Semantic Microblogging !

More than ever, the Semantic Web is becoming reality as it is an integrated component of the Web we are browsing everyday - be it the Open Linked Data movement that nowadays exposes over 10 billion triples of RDF or the annotated and structured information available on Web pages used by major search engines, such as Yahoo! SearchMonkey and Google. Moreover, social data about people and their interaction is made available in machine-understandable format in projects like FOAF or SIOC. Facing this amount of data, privacy and trust consideration is an important step to take right now. The challenging research questions arising from this movement include:

• How do people know that the data gathered from several sources for reasoning purposes can be trusted?
• How can one avoid that personal data exposed on the Semantic Web will be combined with other available semantic data in a way that sensitive information may be revealed?
• How shall a safe reasoning process look like that does not end up in a conflict only because a single Semantic Web peer exposed a contradiction?

As last year, we expect both theoretical and practical contributions (including demos) on these hot topics.
For more information about the workshop, deadlines, etc. please check the SPOT2010 website.

It has been drawn based on the cloud history and the original ESWC2007 poster. Hopefully, such graph can be automatically done when we'll get a machine-readable description of that cloud, e.g. using voiD.

• My personal URI redirects to a document about myself using a 303 redirect;
• This document is not a native RDF/XML or turtle file, but an XHTML documents embedding RDFa annotations.

Indeed, the current FOAF-SSL online certificate generation tool relies only on personal URIs (or WebID if you prefer) that corresponds to fragments of RDF documents, as in http://example.org/foaf.rdf#me. However, it shouldn't be an issue for the clients, since most recent Semantic Web applications should be able to deal with such scenarios of redirect and RDFa. And indeed, it worked perfectly - at least on the two FOAF-SSL clients that I tried with Firefox (something wrong in Safari not asking for any certificate)

It took me only a few minutes to set-up and try this complete use-case (well, actually a bit more to test it, until I discovered the Safari issue):

• Create my certificate and upload it in my browser using this tutorial;
• Generate the related RDFa snippet corresponding to the certificate, see below or in ESW Wiki;

<div about="#cert" typeof="rsa:RSAPublicKey">
  <div rel="cert:identity" href="http://apassant.net/alex"></div>
  <div rel="rsa:public_exponent">
    <div property="cert:decimal" content="65537"></div>
  </div>
  <div rel="rsa:modulus">
    <div property="cert:hex" content="8af4cb6d6ec004bd28c08d37f63301a3e63ddfb812475c679cf073c4dc7328bd20dadb9654d4fa588f155ca0
5e7ca61a6898fbace156edb650d2109ecee65e7f93a2a26b3928d3b97feeb7aa062e3767f4fadfcf169a223f4a621583a7f6fd8992f65ef1d17bc42392f
2d6831993c49187e8bdba42e5e9a018328de026813a9f"></div>
  </div>
</div>

• Add the cert and rsa namespace in my Drupal template header - even easier as I already have the other namespaces here, as well as GRDDL profile and correct DTD)
• Edit my about page (that is provided via the 303 redirection from my URI) with Drupal to add the RDFa snippet in it;
• Successfuly log-in to a test-page (that uses ARC2 - which natively supports that 303+RDFa scenarios, hence enabling that RDFa FOAF-SSL scenario) and in the Cheese lovers club; below is the output of the first one

It's now time for related applications, and I hope I'll be able to write more about it in the future.

$s = new FStore('demo');
$s->import('http://rdfs.org/sioc/ns');
$s->query("select ?s where { <http://rdfs.org/sioc/ns#Item> ?s ?o }");
$s->delete('http://rdfs.org/sioc/ns');

The 2nd Social Data on the Web workshop (SDoW2009) co-located with the 8th International Semantic Web Conference (ISWC2009) aims to bring together researchers, developers and practitioners involved in semantically-enhancing social media websites, as well as academics researching more formal aspect of these interactions between the Semantic Web and Social Web.

Since its first steps in 2001, many research issues have been tackled by the Semantic Web community such as data formalism for knowledge representation, data querying and scalability, or reasoning and inferencing. More recently, Web 2.0 offered new perspectives regarding information sharing, annotation, and social networking on the Web. It opens new research areas for the Semantic Web which has an important role to play to lead to the emergence of a Social Semantic Web that should provide novel services to end-users, combining the best of both Semantic Web and Web 2.0 worlds. To achieve this goal, various tasks and features are needed from data modeling and lightweight ontologies, to knowledge and social networks portability as well as ways to interlink data between Social Media websites, leveraging proprietary data silos to a Giant Global Graph.

Following the successful SDoW2008 workshop at ISWC2008, SDoW2009 aims to bring together Semantic Web experts and Web 2.0 practitioners and users to discuss the application of semantic technologies to data from the Social Web.

The workshop welcome submission of short and full papers as well as demos of applications combining Semantic Web and Social Web technologies - all due to the 10th of August.