**DiTTO**, which stands for *Diagrams Transformation inTo OWL* (version 1.1, dated 25 March 2014),
is a Web application that is able to translate diagrams expressed either in
E/R crow’s foot notation or Graffoo and created with yEd,
an open source application to quickly and effectively generate high-quality diagrams,
into OWL ontologies.

If you choose to specify E/R diagrams, DiTTO allows one to choose what E/R semantics to apply for the transformation according to three alternative conversion strategies, which depends on the application of two assumptions:

**global semantics (GS)**is a characteristic of OWL ontologies (but not typically of E/R), and has the effect of unifying the formal interpretation of domain and range axioms, property characteristics, and all the restrictions that act at a global level. When GS does not hold, one is not allowed to assume such unification, even when the axioms regard two constants with the same name;**unique name assumption (UNA)**, which is a characteristic in E/R semantics (but not of OWL), and whose consequence is that two objects named differently always refer to different entities in the world.

In particular, the *minimal strategy* interprets the semantics of E/R in its purest form by not using GS, while using UNA,
the *intermediate strategy* does not use either GS or UNA, and finally the *maximal strategy*, which is the closest
to OWL semantics, use GS, but UNA does not hold.

DiTTO is an open source tool hosted by GitHub. The exemplar yEd diagrams, in E/R crow's foot and Graffoo, described in the following pictures are available (E/R diagram and Graffoo diagram) so as to test the service.

- Gangemi, A., Peroni, S. (2013). DiTTO: Diagrams Transformation inTo OWL. In Proceedings of the ISWC 2013 Posters & Demos Track (ISWC-PD 2013), CEUR Workshop Proceedings. Aachen, Germany: CEUR-WS.org. http://ceur-ws.org/Vol-1035/iswc2013_demo_2.pdf.

Silvio Peroni is a postdoc from the University of Bologna and, for this project, part-time collaborator with the Semantic Technologies Lab at CNR (i.e. the Italian National Research Council). He created and maintains DiTTO, and he have developed the XSLT files to convert E/R diagrams into OWL. He maintains a blog about his research.

Riccardo Falco has a Bachelor Degree in Computer Science. His Bachelor Thesis concerned the extension of DiTTO with additional XSLT files to convert Graffoo diagrams into OWL.