Preface
This volume contains the proceedings of the Sixth International Workshop on Graph
Computation Models (GCM 2015). The workshop took place in L’Aquila, Italy, on 20
July 2015, as part of STAF 2015 (Software Technologies: Applications and Foundations)
and co-located with ICGT 2015 (International Conference on Graph Transformation).
The aim of the GCM workshop series is to bring together researchers interested in all
aspects of computation models based on graphs and graph transformation. It promotes
the cross-fertilizing exchange of ideas and experiences among researchers and students
from the different communities interested in the foundations, applications, and imple-
mentations of graph computation models.
   Previous editions of GCM were held in Natal (Brazil) in 2006, in Leicester (UK) in
2008, in Enschede (The Netherlands) in 2010, in Bremen (Germany) in 2012, and in
York (UK) in 2014.
   These proceedings contain the abstract of an invited talk and seven accepted papers.
Each submission was carefully reviewed by three Programme Committee members. The
topics of the papers include applications of graph transformation to parsing and policy
modelling, parallel execution models of graph transformation, the theoretical foundations
of graph transformation with attributes, and the verification of graph programs. Revised
selected papers from these proceedings will be published as an issue of the international
journal Electronic Communications of the EASST.
   I would like to thank all who contributed to the success of GCM 2015, especially the
authors and the Programme Committee for its work in the selection process. I would
also like to thank the ICGT 2015 Programme Chairs and the organizers of STAF 2015
for their support in organizing GCM 2015.


July 20, 2015
                                                                           Detlef Plump
L’Aquila, Italy