- Lead developer of Semantic MediaWiki
- Co-developer of the ELK Reasoner
- President of the Open Semantic Data Association e.V.
- Member of the new W3C Web Ontology Language (OWL) working group (as of 2012, it still exists, dormant, waiting for XML Schema to finish)
- Former member of W3C Rule Interchange Format (RIF) working group
- Maintainer of semanticweb.org, the Semantic Web community portal
Organisation of events and journals
Tutorials and summer school lectures are listed under teaching.
- WWW 2016: 25th International WWW Conference (Area Chair “Semantics and Big Data")
- ISWC 2016: 15th International Semantic Web Conference (In-Use Track Chair)
- KI 2015: 38th German Conference on Artificial Intelligence (Program Chair)
- Journal of Web Semantics Special Issue “Knowledge Graphs" (Guest Editor)
- KI 2014: 37th German Conference on Artificial Intelligence (chair for doctoral program)
- AAAI 2013: 27th Conference on Artificial Intelligence; Program Chair "AI on the Web"
- DL 2013: 26th International Workshop on Description Logics; Program Chair
- ESWC 2012: 9th Extended Semantic Web Conference; Reasoning Track Programme Chair
- RR 2012: 6th International Conference on Web Reasoning and Rule Systems; Programme Chair
- PODS 2012: 31st ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems; Proceedings & Publicity Chair
- OWLED 2008 (EU), the 5th International Workshop on OWL: Experiences and Directions, Karlsruhe, Germany, Oct 26 – 27 2008, local organisation.
- SWKM 2008, the 2008 Workshop on Social Web and Knowledge Management at WWW 2008, Bejing, China, April 22nd, 2008.
Reviewing for conferences and journals
I have been reviewing (on programme committees or individual requests) for the following journals:
- Journal of Artificial Intelligence Research
- Journal of Web Semantics
- Journal of Automated Reasoning
- Journal of Symbolic Computation, reviewer for special issue on Automated Deduction: Decidability, Complexity, Tractability, 2008
- International Journal of Computer Mathematics, 2008
- Journal of Universal Computer Science, PC member of special issue on Ontologies and their Applications, JUCS 13(12), 2007
- Semantic Web Journal
I serve or have served as a programme committee member of the following events:
- KR 2014, the 14th International Conference on Principles of Knowledge Representation and Reasoning
- ISWC 2014, the 13th International Semantic Web Conference
- ESWC 2014, the 11th European Semantic Web Conference
- DL 2014, the 27th International Workshop on Description Logics, Vienna, Austria, July 17 – 20 2014
- IJCAI 2013, the 23rd International Joint Conference on Artificial Intelligence
See also the talk section in publications.
- Keynote “Wikidata: The Next Big Thing for Wikipedia” at 3rd Russian Conference on Knowledge Engineering and Semantic Web, St. Petersburg, Russia, 2012
- Keynote “Small OWLs at Large! But Where are They Going?” at 9th OWL: Experiences and Directions Workshop, Heraklion, Greece, 2012
- Speaker at Reasoning Web Summer School 2007 on “Reasoning in Semantic Wikis”
- Invited talk at the Semantic Web Technology Showcase 2007, Vienna, Austria (colocated with ESTC2007, the first European Semantic Technology Conference) on “Practical Reasoning with OWL and Rules”