Section: New Software and Platforms

Alignment API

Participants : Jérôme Euzenat [Correspondent] , Jérôme David, Nicolas Guillouet, Armen Inants.

We have designed a format for expressing alignments in a uniform way [2] . The goal of this format is to share available alignments on the web. It should help systems using alignments, e.g., mediators, translators, to take advantage of any matching algorithm and it will help matching algorithms to be used in many different tasks. This format is expressed in rdf , so it is freely extensible.

The api itself [2] is a Java description of tools for accessing the common format. It defines five main interfaces (OntologyNetwork, Alignment, Cell, Relation and Evaluator).

We provide an implementation for this api which can be used for producing transformations, rules or bridge axioms independently from the algorithm which produced the alignment. The proposed implementation features:

• a base implementation of the interfaces with all useful facilities;

• a library of algebras of relations;

• a library of sample matchers;

• a library of renderers (xslt , rdf , skos , swrl , owl , c-owl , sparql );

• a library of evaluators (various generalisation of precision/recall, precision/recall graphs);

• a flexible test generation framework which allows for generating evaluation datasets;

• a library of wrappers for several ontology api ;

• a parser for the format.

To instanciate the api , it is sufficient to refine the base implementation by implementing the align() method. Doing so, the new implementation will benefit from all the services already implemented in the base implementation.

In 2015, we further integrated the implementation of link keys and their transformations into sparql queries (§ 3.3 ). We developed the transformation aspect of the edoal language. Finally, we provided the interface with alignment algebras into the api implementation (§ 7.1.2 ).

We have developed, on top of the Alignment api , an Alignment server that can be used by remote clients for matching ontologies and for storing and sharing alignments. It is developed as an extensible platform which allows to plug-in new interfaces. The Alignment server can be accessed through html , web service (soap and rest ) and agent communication interfaces. It has been used this year in the Ready4SmartCities project (§ 9.2.1.1 ) [14] , [20] .

The Alignment api is used in the Ontology Alignment Evaluation Initiative data and result processing (§ 7.1.1 ). It is also used by more than 50 other teams worldwide.

The Alignment api is freely available since december 2003, under the lgpl licence, at http://alignapi.gforge.inria.fr .