inkdroid

Via Ivan Herman I learned that the Semantic Web Use Cases use concepts from lcsh.info. For example look at the RDFa in this case study for the Digital Music Archive for the Norwegian National Broadcaster. You can also look at the Document metadata in a linked data browser like OpenLink. Click on the “Document” and then on the various subject “concepts” and you’ll see the linked data browser go out and fetch the triples from lcsh.info for “Semantic Web” and “Broadcasting”.

One of the downsides to linked-data browsers (for me) is that they hide a bit of what’s going on. Of course this is by-design. For a more rdf centric view on the data take a look at this output of rapper.

ed@curry:~$ rapper -o turtle http://www.w3.org/2001/sw/sweo/public/UseCases/NRK/
rapper: Serializing with serializer turtle
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix bibo: <http://purl.org/ontology/bibo/> .
@prefix dc: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xhv: <http://www.w3.org/1999/xhtml/vocab#> .
@prefix xml: <http://www.w3.org/XML/1998/namespace> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<http://www.w3.org/2001/sw/sweo/public/UseCases/NRK/>
    a bibo:Document;
    dc:rights "\u00A9 Copyright 2007, ESIS, NRK."@en-us;
    dc:subject <http://lcsh.info/sh85017004#concept>, <http://lcsh.info/sh2002000569#concept>;
    dc:date "2007-09"^^xsd:dateTime;
    dc:title "Case Study: A Digital Music Archive (DMA) for the Norwegian National Broadcaster (NRK) using Semantic Web techniques"@en-us;
    bibo:distributor <http://www.w3.org/>;
    bibo:authorList (
        [
            a foaf:Person;
            foaf:workplaceHomepage <http://www.esis.no>;
            foaf:name "Dr. Robert H.P. Engels"@nl
        ]
        [
            a foaf:Person;
            foaf:workplaceHomepage <http://www.nrk.no>;
            foaf:name "Jon Roar T\u00F8nnesen"@no
        ]
    ) .

<http://www.w3.org/2001/sw/sweo/public/UseCases/NRK/Overview.html>
    xhv:stylesheet <http://www.w3.org/2001/sw/sweo/public/UseCases/style/ucstyle.css> .

You can see Ivan’s using the dc, foaf, skos and bibo vocabularies, and the links out lcsh Concepts. Fun stuff.

If you’ve already caught the micro-blogging bug identi.ca is an interesting twitter clone for a variety of reasons…not the least of which is that it’s an open source project, and has been designed to run in a decentralized way. The thing I was pleasantly surprised to see was FOAF exports like this for user networks, and HTTP URIs for foaf:Person resources:

ed@hammer:~$ curl -I http://identi.ca/user/6104
HTTP/1.1 302 Found
Date: Fri, 11 Jul 2008 12:58:56 GMT
Server: Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.1 with Suhosin-Patch
X-Powered-By: PHP/5.2.4-2ubuntu5.1
Status: 303 See Other
Location: http://identi.ca/edsu
Content-Type: text/html

It looks like there’s a slight bug in the way the HTTP status is being returned, but clearly the intent was to do the right thing by httpRange-14. If I have time I’ll get laconi.ca running locally so I can confirm the bug, and attempt a fix.

It’s also cool to see that Evan Prodromou (the lead developer, and creator of identi.ca and laconi.ca) has opened a couple tickets for adding RDFa to various pages. If I have the time this would be a fun hack as well. I’d also like to take a stab at doing conneg at foaf:Person URIs to enable this sorta thing:

ed@hammer:~$ curl -I --header "Content-type: application/rdf+xml" http://identi.ca/user/6104
HTTP/1.1 303 See Other
Date: Fri, 11 Jul 2008 13:08:42 GMT
Server: Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.1 with Suhosin-Patch
X-Powered-By: PHP/5.2.4-2ubuntu5.1
Location: http://identi.ca/edsu/foaf

instead of what happens currently:

ed@hammer:~$ curl -I --header "Content-type: application/rdf+xml" http://identi.ca/user/6104
HTTP/1.1 302 Found
Date: Fri, 11 Jul 2008 13:08:42 GMT
Server: Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.1 with Suhosin-Patch
X-Powered-By: PHP/5.2.4-2ubuntu5.1
Status: 303 See Other
Location: http://identi.ca/edsu
Content-Type: text/html

I guess this is also just a complicated way of saying I’m edsu on identi.ca–and that the opportunity to learn more about OAuth and XMPP is a compelling enough reason alone for me to make the switch.