The following post is from Primavera De Filippi, representative of Creative Commons France and coordinator of the Open Knowledge Foundation’s Public Domain Working Group.

Many people recognise the value of works which are in the public domain (e.g. the works of Shakespeare, Italian renaissance paintings, classical music, etc). However, it is often difficult for people to determine whether a work has fallen into the public domain in a particular jurisdiction. In order to address this problem, the Open Knowledge Foundation has undertaken the development of the public domain calculators, a series of software applications specifically designed to identify the legal status of a work in any given jurisdiction, by gathering relevant data concerning the work (e.g. date of publication, birth/death date of the author, etc) and processing it through a set of rules that reflect the national implementations of the copyright regime.
A new version of the public domain calculators has recently been released and is available at github.
The public domain calculators are now linked with the national copyright flowcharts of developed as part of the Europeana project. The back-end has been rewritten to allow for national calculators to be written as simple RDF files that subsist independently of the underlying code.
  • Graphm2rdf.rb is a converter that takes a flowchart from the Europeana project (in Graphmlz format) to produce a new flowchart (in RDF format) that describes the national copyright regime according to a specifically designed ontology Flow 0.1 (available at http://bedlam.dk/flow/0.1).
  • Metadata[n].rdf are the metadata files taken from a database describing a particular work in RDF format.
  • Map.rdf provides a link between the questions from Flowchart to the answers in the metadata files by means of specific Sparql queries.
  • Reasoner.py is the actual public domain calculator. It takes those 3 files as an input: Flowchart.rdf (national flowchart), map.rdf (national calculator), and metadata.rdf (work metadata), process the whole thing and declares whether or not the work described in metadata.rdf is in the public domain according to the national copyright regime.
The advantage of this approach is that it makes it easier to create new calculators as new flowcharts gets created or updated. Since the calculators are simple RDF files,  no programming skills are necessary to implement them, except for some decent knowledge of Sparql.
The code is very recent and is still under development. Anyone interested please don’t hesitate to check it out!