RDF

Today I talked with Thomas Hochhaltinger from ebSemantics, a project of "Smart Information Systems", an Austrian company that developed MyOntology.org a collaborative ontology designing platform with ontologies for consumer electronics goods.

Reuters released a web service called Open Calais. It is built on <a href=''http://www.clearforest.com/">clear forest technology that has been around for a while.

You can throw text at it and get tags organized by country, personalities, industry terms, ... in RDF format back. It is of better accuracy than http://tagger.flaptor.com/findtags, http://tagthe.net or yahoo terms extraction API (http://www.programmableweb.com/api/yahoo-term-extraction, http://drupal.org/project/yahoo_terms)

You can try it here:
http://autotagger.opensynapse.net/

KarenS has kicked off a discussion on CCK field structure for core in D7. It's also webchick's itch of the week.

David Strauss is already commenting, and has experience in RDF from the Internet Archive, but it would be good to have other experienced people giving this the once over. Since these fields are likely to be a major way that people "transparently" create subject/predicate/object relationships, we better get this right (and performant, working on shared hosts, etc. etc.).

In regards to the Semantic Web developments announced recently about Drupal 7, I have posted a blog entry at SitePoint and also posted to the Linking Open Data mail list.

This is the beginnings of a design specification proposal for an abstracted API for implementing web services within Drupal 7. This allows Drupal to act as both a server and client for web services in any protocol medium (XML-RPC, RDF, RSS, JSON, etc). It is the combined efforts from a number of people at Druplicon including Marc Ingram, Scott Nelson, Nedjo Rogers, Dmitri Gaskin, etc.

Services API

This is the 5-minute "video from the future" demo presented by Dries in his State of Drupal keynote presentation at Drupalcon Boston 2008. The video demonstrates some of the mashup capabilities of an RDF and SPARQL-enabled Drupal as envisioned by Dries for the upcoming Drupal 7.x release. The version of the demo below includes the original narration by Ben Lavender (the audio from Dries's actual presentation is also available - the RDF material starts after the 52m:30s marker).

I'd like to share some quick thoughts on how Drupal Data could be described in RDF. The attached schema represents the mappings between the current Drupal data structure and the proposed RDF Schema, reusing existing ontologies such as Dublin Core, FOAF, SIOC and SKOS.

The green circles represent the Drupal objects (node, revision, user, role, term), with their equivalent RDF class. The rectangles are the values used in Drupal. It's important to differentiate a class from its actual instances (resources) which are each defined by a unique URI, see the examples below. This schema is meant to be simple, incomplete, and to show the main core features.
Comment and Node are 2 different elements in Drupal, they can be combined in the same Class with the recursive property sioc:has_reply (Comment as Node). Node and Revision objects are separate here as they are in the Drupal Data structure, but they could fundamentally be merged as well.

I presented SIOC at DrupalCon Barcelona, and showed how it can be used to describe online communities. The SIOC sioc:Item class which I used here as equivalent of a Node is a broad Class with many sub-types: AddressBook, AnnotationSet, AudioChannel, BookmarkFolder, MailingList, MessageBoard, BlogPost, BoardPost, WikiArticle... See the SIOC Types Module for more details.

Just a quick note that nedjo posted a note about Services module going into core. This would allow use of XML-RPC, JSON, RSS, REST, SOAP and more to be loaded through a common Services API.

A Code Sprint will take place in Boston this coming Friday that will focus on the inclusion of this new Services API.

Following up on my previous post introducing the in-progress RDF API for Drupal 6.x, I'm going to be, bit by bit, posting some of the materials that I've earlier put together internally for the project this is being developed for. Development of this project is supported through M.C. Dean and MakaluMedia on behalf of their clients.

I've been working on an RDF API for Drupal 6.x for a few months now, but have been reluctant to much discuss it publicly until such time that I had something that was viable and (dare I say it) usable. Given that I've been fortunate enough to recently find funding for part of this work, and that certain key people (thanks Boris and Ivan) have encouraged me to be less of an introvert, I will in the immediate future be doing a series of posts about the project.