It feels strange, but last Friday, after a good 7 1/2 years (that’s 2829 days!), I finally had my last day at DERI, the Digital Enterprise Resarch Institute at the National University of Ireland in Galway.

Coming from a background as a linguist and knowing very little about the Semantic Web, I started as a fresh PhD student in January 2004, when DERI was still only a handful of researchers. Very few people had ever heard about this “Semantic Web” (let alone “linked data” – that label was only coined a few years later), and those who did mostly considered it to be a rather far-fetched, purely academic exercise. I experienced the somewhat crazy early years at DERI (read about it in the paper…), saw the institute grow, change management, change location and eventually turn into the largest (currently 137 members) and probably most successful SW research institute world-wide. I’m pretty sure that for many if not most SW or linked data-related projects and activities you will come across today, there will be someone involved who either did or does work at DERI. Or someone who will work at DERI in the future – during the almost 8 years I have spent there, many outstanding personalities I met in the community eventually joined our little institute.

I experienced DERI as a fantastic place to work: I learned an immense amount of things (skills and experiences that definitely helped me find my new job), made good friends from all over the world (some of the for life, I’m sure), had the opportunity to work and engage with some of the most interesting and influential people in the community (both at DERI and in collaboration with outside partners) and even managed to finish a PhD along the way. Of course, part of the DERI experience is the (mostly) beautiful city of Galway, where the institute is located – but that’s a whole different story. I feel privileged having been very close to the centre of a development which saw the idea of a meaningful, machine-interpretable, “smarter” Web evolve from something that was either ignored or laughed at, into something that is now (in one form or the other) on the agenda of virtually all the big players who define what the Web is today – to pick a few arbitrary examples, just look at schema.org (Google, Yahoo!, Microsoft), Opengraph (facebook) or the adoption of linked data by the BBC.

So, now that my time at DERI is over, I’d like to say “thank you” once more to everyone I have met there, worked with, laughed with, argued with, drank Guinness, whiskey and wine with (or coffee and tea), or walked through the rain with – go raibh míle maith agat! We’ll meet again!

Semantic agents are agents which are aware of RDF data and actively request it.

To know whether or not an agent requests RDF, we could look at the header of an individual HTTP request and check if the agent had specified Accept: application/rdf+xml. However, the Apache server log files unfortunately don’t tell us anything about the request header. Luckily though, there is an indirect way of finding out about this. If our linked data site uses best practice content negotiation and 303 redirects, we can look at pairs of requests in the log files. E.g., the Semantic Web Dog Food site uses a particular URI pattern for resources and their HTML and RDF representations. E.g.:

http://data.semanticweb.org/organization/deri-nui-galway

http://data.semanticweb.org/organization/deri-nui-galway/html

http://data.semanticweb.org/organization/deri-nui-galway/rdf

If the plain URI is requested, the server will either redirect to the HTML or the RDF representation, based on what was specified by the agent. Therefore, if we find a request for a plain URI and a request for the corresponding RDF URI, from the same IP address and the same agent, within a short time frame (e.g. 5 seconds), then we can infer that the agent had requested application/rdf+xml and can therefore be classified as a semantic agent.

90.21.243.141 - - [06/Oct/2008:16:07:58 +0100] "GET /organization/vrije-universiteit-amsterdam-the-netherlands HTTP/1.1" 303 7592 "-" "rdflib-2.4.0 (http://rdflib.net/; eikeon@eikeon.com)"
90.21.243.141 - - [06/Oct/2008:16:08:02 +0100] "GET /organization/vrije-universiteit-amsterdam-the-netherlands/rdf HTTP/1.1" 200 45358 "-" "rdflib-2.4.0 (http://rdflib.net/; eikeon@eikeon.com)"

The example above shows this: the “rdflib.net” agent requested the plain URI .../organization/vrije-universiteit-amsterdam-the-netherlands and was 303 redirected to .../organization/vrije-universiteit-amsterdam-the-netherlands/rdf a few seconds later. From this we can automatically infer that “rdflib.net” is a semantic agent.

A list of 423 semantic agents found in this way for the dog food site from 10/2008-10/2009 is here. Looking at the list, we can find a lot of agents that are clearly “semantic”, such as the “SindiceFetcher” or a SIOC browser. However, most of them are actually not what I would normally consider “semantic”, such as hordes of “Mozilla”-branded agents or dodgy looking bots. More research is awaiting…

All the different groups and their results can be found on this wiki page, so I’ll just mention a few things here, such as vocabularies for meeting minutes, calls for papers or real estate (not forgetting the very important Ear Worm vocabulary), more work on a SW starter pack, discussions and work on Microformat-RDF mappings and RDFa in Drupal.

Luckily Galway was on its best behaviour – I think it didn’t rain at all during the two days. Looking forward to more VoCamps in other places soon!

• There are more and more Semantic Web applications out there, and they are getting slicker and more user-friendly every year. The demo and poster session and the Semantic Web challenges clearly showed that. Some highlights were probably paggr (semantic widgets) by Benjamin Nowack and several different apps that make use of mobile technologies (on the iPhone, no less). Incidentally, those two also won the first and second prize in the challenge (Benjamin won this for the second time already, after having won with CONFOTO (seems to be offline at the moment) at ISWC2005.
• Interestingly for me, a lot of people are working on solutions to make SPARQL-querying more accessible to end users. There is our own work on a SPARQL builder component for Konduit, there is the web-based graphical interface NITELIGHT, and some cool SPARQL extensions by Benjamin Nowack (again!). While those were all presented during the poster session, I also talked to some other people in the coffee breaks who told me about their work in this area – this clearly seems to be an area where a lot of developments and improvements are going to surface soon!
• OpenCyc – this is of course not really a new development, but after having attended the tutorial of using OpenCyc for the Semantic Web, I’m starting to think that their ontology and knowledge base are, at the very least, a very interesting point of reference for linked open data. Those guys have worked on their ontologies for a long time, and a lot of reasoning technology is already in place. Therefore, if we hook up our linked data to (Open)Cyc terms, the hope is that we can finally have the inferencing magic that people are dreaming of for the Web.
• And finally, to come to the title of this post. I learned the hard way this year that one cannot put enough effort into advertising one’s work and also oneself. I think Richard and I did a pretty good job with the conference metadata this year, and set up a very nice site with a lot of interesting functionality for developers and conference attendees. Unfortunately, we didn’t spend an equal amount of work on making the people at the conference aware of that, with the result that e.g. way too few knew that there was an option to discuss papers online and make those discussion become part of the metadata about the paper. Also, to my surprise, some people even didn’t seem to know that I had been acting as metadata co-chair at all. Note to self: be more proactive next year.

Now, with the help of funding from SWSA and the Nepomuk project, Richard Cyganiak, research intern Venkatram Yadav and me have managed to do a lot of data-cleaning and aligning and redo the whole site as a module on top of the Drupal CMS, with the result that everything is now a lot nicer looking, more user friendly, better interlinked and generally speaking cooler. Thanks a lot also to Stéphane Corlosquet, our local Drupal guru here at DERI, who helped us out with a lot of tricky Drupal questions.

Apropos Drupal: There is an interesting discussion going on at the moment in the Drupal community to add RDF export functionality to the Drupal Core system. What it means is basically exporting the Drupal DB as RDF (SIOC, FOAF, etc.). Somehow, our approach is the exact opposite – we export an RDF-DB through Drupal! Both approaches put together in a meaningful way would probably result in a very cool end product!

So, what can the Dog Food site do for you? Here is a list:

• Browse thousands of people, papers and organisations in your Web browser, …
• … or in a linked data browser – it’s all linked data!
• SPARQL to your heart’s content, making use of the named graphs we have established for each event in the database.
• To support your SPARQL needs, you can also use the snorql tool on the site.
• Comment and discuss each paper. All papers and comments are good citizens of the SIOC-osphere!
• Do a full-text search on the data on the site.
• Enjoy eye-candy like the map of all organisations in the repository (provided we have their geo-coordinates).

The whole event was pretty organic and loosely organised. Compared to big, official events with lots of pretty boring talks (not saying that _all_ talks are always boring), VoCamp was refreshingly fun and engaging. I actually had the feeling that I was doing something useful. Ad-hoc groups formed on the spot, working on varied topics such as an IRC vocabulary, a whiskey ontology, something which could be called a “vocabulary starter pack for SemWeb newbies”, an evidence ontology, bio-med vocabularies, etc. The idea is that we will have a number of VoCamps in rapid succession (the next one will be in November here in Galway), and so, even though probably none of the individual topics will have enourmous impact just now, I think VoCamp can definitely create a lot of momentum over time.

On Thursday, we planned to take the opportunity to join the Oxford SWIG meeting, but unfortunately there didn’t seem to be a lot of Semantic Web interest just that evening in Oxford. However, I did manage to say hello to Kal Ahmed of TM4J (Topic Maps) fame!