Exploring Linked Data with Gremlin

Gremlin is a free Java/Groovy system for traversing graphs, including but not limited to RDF. This post is based on example code from Marko Rodriguez (@twarko) and the Gremlin wiki and mailing list. The test run below goes pretty slowly when run with 4 or 5 loops, since it uses the Web as its database, via […]

Skosdex: SKOS utilities via jruby

I just announced this on the public-esw-thes and public-rdf-ruby lists. I started to make a Ruby API for SKOS. Example code snippet from the readme.txt (see that link for the corresponding output): require “src/jena_skos” s1 = SKOS.new(“http://norman.walsh.name/knows/taxonomy”) s1.read(“http://www.wasab.dk/morten/blog/archives/author/mortenf/skos.rdf” ) s1.read(“file:samples/archives.rdf”) s1.concepts.each_pair do |url,c| puts “SKOS: #{url} label: #{c.prefLabel}” end c1 = s1.concepts[“http://www.ukat.org.uk/thesaurus/concept/1366”] # Agronomy puts […]

Beautiful plumage: Topic Maps Not Dead Yet

Echoing recent discussion of Semantic Web “Killer Apps”, an “are Topic Maps dead?” thread on the topicmaps mailing list. Signs of life offered include www.fuzzzy.com (‘Collaborative, semantic and democratic social bookmarking’, Topic Maps meet social networking; featured tag: ‘topic maps‘) and a longer-list from Are Gulbrandsen who suggests a predictable hype-cycle dropoff is occuring, as […]

JQbus: social graph query with XMPP/SPARQL

Righto, it’s about time I wrote this one up. One of my last deeds at W3C before leaving at the end of 2005, was to begin the specification of an XMPP binding of the SPARQL querying protocol. For the acronym averse, a quick recap. XMPP is the name the IETF give to the Jabber messaging […]

Venn diagrams for Groups UI

This is the result of feeding a relatively small list of groups and their members to the VennMaster java tool. I’ve been looking for swooshy automatic layout tools that might help with interactive visualisation of ‘social graph’ data where people can be clustered by their membership of various groups. I also wanted to explore the […]

Imagemap magic

I’ve always found HTML imagemaps to be a curiously neglected technology. They seem somehow to evoke the Web of the mid-to-late 90s, to be terribly ‘1.0’. But there’s glue in the old horse yet… A client-side HTML imagemap lets you associate links (and via Javascript, behaviour) with regions of an image. As such, they’re a […]

SQL, OpenOffice: would a JDBC driver for SPARQL protocol make sense?

I’d like to have access to my SPARQL data from desktop tools like OpenOffice’s spreadsheet. Apparently it can talk to remote databases via JDBC and OBDBC, both for the spreadsheet and database tools within OpenOffice. Many years ago, pre-SPARQL, I hassled Libby into making her Squish RDF query system talk JDBC. There have been related […]

Amazon EC2: My 131 cents

Early this afternoon, I got it into my head to try out Amazon’s “Elastic Compute Cloud” (EC2) service. I’m quite impressed. The bill so far, after some playing around, is 1.31 USD. I’ve had the default “getting started” Fedora Linux box up and running for maybe 7 hours, as well as trying out machine images […]


I’ve just made Widgetarians.org, a Planet-based aggregator of Widgety stuff. The contents are somewhat ad-hoc, and will evolve in unpredictable ways as people publish and fix feeds, and as I hear about new sites. For example, at the time of writing I couldn’t find any working public feeds for the great things the Opera folks […]

SPARQLing Protégé-OWL Jena integration

The Jena ARQ SPARQL engine has been very rapidly integrated into Protégé. Nice work from Holger Knublauch, and from Andy Seaborne who explained how Protégé’s native RDF Java structures could manifest themselves via Jena interfaces so that the ARP query engine could work against Protégé data. He also gave a handy overview of the ARP […]