RDF/RDFa now part of Drupal core

Hi,

After several months of research, coding, sprints and patch reviews, the
main RDF patch has been committed to Drupal core! (Thanks Dries!) This
introduces a basic RDF API which maps the Drupal data structure to RDF.
These mappings are then automatically exported as RDFa throughout the site.

To give you a sneak preview of the code it generates, I've put up a Drupal 7
site at http://drupalrdf.openspring.net/ for testing purposes. We still have
some bugs to fix but the bulk of it is working. I'm hoping to get feedback
from the RDF community about the RDFa it generates. Please try it with your
favorite RDFa parser and report any bug you encounter. You will find some
dummy RDF properties/classes sometimes but we'll fix them soon. Note that
the RDF mappings are fairly independent from the the actual API since the
mapping definitions are centralized [2] and are not hardcoded in the HTML
(hereby allowing exports in other RDF serialization formats).

Some examples:
A blog post with comments http://drupalrdf.openspring.net/node/3
Forum page http://drupalrdf.openspring.net/node/4
Static page http://drupalrdf.openspring.net/about

Drupal 7 is still in development phase. The first beta releases should come
out in the coming months, and the final release in the new year. Our
priority is to fix all remaining bugs [3] and then agree on the best
mappings which will come pre-installed in core. I will send more emails on
specific issues, so if you're interested make sure to subscribe to
foaf-dev@lists.foaf-project.org, sioc-dev@googlegroups.com and
public-rdf-in-xhtml-tf@w3.org.

For those attending ISWC next week, I'll present the research work which was
used to build RDF in Drupal core, see paper [4]. See you on Tuesday
afternoon in the Semantic Web In Use Track!

Stephane.

[1] RDF mapping API http://api.drupal.org/api/function/hook_rdf_mapping/7
[2] Open issues
http://drupal.org/project/issues/search/drupal?status[]=Open&issue_tags=RDF
[3] Report an issue http://drupal.org/project/issues/drupal
[4] Produce and Consume Linked Data with Drupal!
http://openspring.net/sites/openspring.net/files/corl-etal-2009iswc.pdf