6th International Workshop Weighted Automata: Theory and Applications WATA 2012 Dresden, Germany, May 29 - June 2, 2012 edited by Manfred Droste and Heiko Vogler Preface This report contains the programme and the abstracts of lectures delivered at the workshop Weighted Automata: Theory and Applications which took place at Technische Universit¨at Dresden, May 29 - June 2, 2012. This workshop covered all aspects of weighted automata, ranging from the theory of weighted automata and quantitative logics to applications for real-time systems and natural language processing. The workshop was attended by 67 participants from 15 countries. Three tutorials were given by Javier Esparza and Michael Luttenberger (Munich, Germany) Orna Kupferman (Jerusalem, Israel) Anoop Sarkar (Burnaby, Canada). In addition, seven survey lectures were presented by Frank Drewes (Ume˚ a, Sweden) Zolt´ an ´ Esik (Szeged, Hungary) Paul Gastin (Cachan, France) Laura Kallmeyer (D¨ usseldorf, Germany) Kevin Knight (Los Angeles, USA) Kim Larsen (Aalborg, Denmark) Karin Quaas (Leipzig, Germany). There was a special session honoring Werner Kuich on the occasion of his 70 th birthday. Furthermore 28 talks were selected as technical contributions. The workshop was organized jointly by the Chair of Automata and Formal Languages of Leipzig University and the Chair of Foundations of Programming of Technische Univer- sit¨atDresden. For financial support we would like to thank the German Research Foun- dation (DFG), Faculty of Computer Science (TU Dresden), Gesellschaft von Freunden und F¨orderern der TU Dresden, and the International Center for Computational Logic. Call for Papers The journal Theoretical Computer Science TCS-A has agreed to publish a special issue on the topic of this workshop. Submissions could be either survey articles or research papers, they will be refereed according to the usual high journal standards. Participation in the workshop is encouraged, but is not a prerequisite for submission. Authors are asked to submit their contribution preferably in PDF to each of the three editors of the special issue. Please send your files to: Manfred Droste droste@informatik.uni-leipzig.de Zolt´ an ´ Esik ze@inf.u-szeged.hu Heiko Vogler heiko.vogler@tu-dresden.de The deadline for submission is July 30, 2012. We intend to ensure a quick refereeing process. Manfred Droste and Heiko Vogler i