Preface This volume contains the papers presented at ORE 2014: The 3rd OWL Rea- soner Evaluation Workshop held on July 13, 2014 in Vienna (co-located with the Vienna Summer of Logic, VSL). The committee decided to accept 11 papers (5 Evaluation and Benchmarks papers, 3 papers about a reasoner or reasoning techniques, and 3 papers describing an ontology). Each submission was reviewed by at least 3 program committee members. OWL is a logic-based ontology language standard designed to promote inter- operability, particularly in the context of the (Semantic) Web. The standard has encouraged the development of numerous OWL reasoning systems, and such systems are already key components of many applications. The goal of ORE is to bring together the developers and users of reasoners for (subsets of) OWL, including systems focusing on both intensional (ontology) and extensional (data) query answering. The workshop will give developers a perfect opportunity to promote their systems. In addition to workshop paper submissions, ORE 2014 also included a com- petition in which OWL reasoners were faced with different reasoning tasks. The competition included six disciplines in which reasoners could compete: ontology classification, consistency checking, and realisation each for OWL EL and OWL DL reasoners. The tasks were performed on several large corpora of real-life OWL ontologies obtained from the web, as well as user-submitted ontologies which were found to be challenging for reasoners. August 5, 2014 Samantha Bail Birte Glimm Ernesto Jimenez-Ruiz Nicolas Matentzoglu Bijan Parsia Andreas Steigmiller i Acknowledgements We thank all members of the program committee, competition organisers, addi- tional reviewers, authors of the submitted papers, developers of the submitted reasoners and ontologies, and local organizers for their invaluable effort. We also thank Konstantin Korovin (supported by the Royal Society grant RG080491) at the University of Manchester who kindly provided us with the PC cluster for the competition. We also gratefully acknowledge the support of our sponsors. In particular, we thank the main workshop sponsors: the DL workshop (http://dl.kr.org/) and B2i Healthcare (https://www.b2international.com/). We would also like to acknowledge that the work of the ORE organisers was greatly simplified by using the EasyChair conference management system (http://www.easychair.org) and the CEUR Workshop Proceedings publica- tion service (http://ceur-ws.org/). ii Organisers, PC Chairs Samantha Bail Flatiron Health, New York Ernesto Jimenez-Ruiz University of Oxford Competition Organisers Birte Glimm University of Ulm Nicolas Matentzoglu University of Manchester Bijan Parsia University of Manchester Andreas Steigmiller University of Ulm Program Committee Ana Armas Oxford University Franz Baader TU Dresden Michel Dumontier Stanford University Christine Golbreich University of Montpellier Janna Hastings European Bioinformatics Institute Yevgeny Kazakov The University of Ulm Pavel Klinov University of Ulm Ilianna Kollia National Technical University of Athens Despoina Magka Yahoo Francisco Martin-Recuerda Universidad Politecnica of Madrid Christian Meilicke University of Mannheim Julian Alfredo Mendez TU Dresden Maria Del Mar Roldan-Garcia Universidad de Malaga Stefan Schlobach Vrije Universiteit Amsterdam Jörg Schönfisch University of Mannheim Weihong Song University of New Brunswick Kavitha Srinivas IBM Research Dmitry Tsarkov The University of Manchester Zhe Wang Griffith University Additional Reviewers Evgeny Kharlamov University of Oxford Markus Krötzsch TU Dresden Marvin Schiller University of Ulm Alessandro Solimando Università di Genova Dmitriy Zheleznyakov University of Oxford iii