1994- Member, Arbeitsgemeinschaft für Medizinisches Bibliothekswesen (AGMB, German Medical Libraries Association)
1994- Member, European Association for Health Information Libraries
1994- Founder and Admin, MEDIBIB-L (mailing list for German-speaking medical librarians)
1994-2001 Founder and Admin, LITI – Literaturliste Internet
1994-2008 Member, Verein Deutscher Bibliothekare
1995 Professional Visit in the USA (National Library of Medicine, Welch Library Baltimore, Taubmann Library Ann Arbor, Shiffman Library Detroit, Health Sciences Library Buffalo)
1995- Member, Medical Libraries Association (MLA) and International Cooperation Section / MLA
1995-1998 Co-Founder and Head, Working group „Medical Academic Libraries“ of the AGMB
1996-2001 Founder and Admin, Homepage of the AGMB
1997-2001 Founder and Chief Editor, GMS Medizin – Bibliothek – Information (vormals AGMB aktuell bzw. medizin-bibliothek-information)
1998-2000 Member, Advisory Board of the DFG project webis
1998-2003 Deputy Chair, AGMB
1999-2002, 2007-2014 National Delegate of Germany, Council of the European Association for Health Information Libraries
2000-2003 Project Manager, BMBF-Project LOTSE
2001-2002 Chair, International Programme Committee 8th EAHIL Conference, Cologne (Report (German))
2002-2008 Member, Advisory Board of DIMDI
2002-2012 Member, Advisory Board of the German National Library of Medicine
2004-2013 Founder and Chief Editor, medinfo weblog
2005 Honorary Award of the Stiftung Medizinische Lehre in recognition of exceptional teaching and commitment to support the students of the Medical Faculty Münster
2007- Member, Editorial Board, Journal of the European Association for Health and Information Libraries
2008-2012 Co-Chair, EAHIL Taskforce Web 2.0
2009 Member, Nature Publishing Group Library Committee
2010 Professional Stay in Indonesia
2010-2014 Member, Library Advisory Committee of UpToDate
2012- Member, AGMB Excellence Price Jury
2014 Member, Horizon Project Expert Panel for Higher Education
2014-2018 Deputy Member, Senate of the University of Munster
2014- Member, Editorial Board PulsSchlag – Magazine of the University Clinic Münster
2015 Gewinner des Wettbewerbs Leuchtturmprojekte an Medizinbibliotheken
2015-2017 Member, Advisory Board of the DFG project MDM-Portal
2018-2020 Member, Library Advisory Board of Thieme Publishing, Stuttgart
2018 Honorary Award of the European Association for Health Information and Libraries in recognition of his contributions to the Association.