The “open data” topic is always in the air and, thanks to the open source world, it is becoming more and more spread.
When we want to manage open data we need to consider 2 types of software:
- linked data applications;
- data catalogs.
The first type is oriented towards the use of triple store databases specialized in store RDF triples, we find solutions like:
- Apache Marmotta (Java, Apache license) which has a Drupal module;
- Callimachus (Java, Apache license);
- Cubicweb (Python, LGPL).
We find as well some REST API which aim to connect to triple stores:
- Apache Stanbol (Java, Apache license) which has a Drupal module in alpha status;
- Open Semantic Framework (PHP, Apache license) which has a Drupal module.
The second type is oriented to the management of the open data:
- CKAN (Python, AGPL 3), which is the most famous data catalog (at European level see: Public Data.eu, EU Open Data portal), there was a tentative from data.gov.uk in creating a connection but they preferred to keep them separately;
- DKAN (PHP, GPL 2), which is based on the famous Drupal (see city of Bonn, Cologne or Czech Ministry of Finance) and aims to be 100% compatible with CKAN.
Drupal has also a couple of interesting modules to connect to triple stores:
Another interesting module is RDFx which allows to manage RDF mapping with Drupal Content types and it works in combination with the RESTWS module so you can have the RDF extraction of a content type by simply adding “.rdf” to your node (for example http://localhost/drupal/node/1.rdf)
Well if you find more open source applications, which might connect to Drupal, let me know :-)