Acknowledgements

The following people have contributed significantly to the organization of the competition:

• To the IPC council for providing extensive comments and offering a lot of helpful suggestions. In particular, to Malte Helmert for inviting us to his university, his assistance and all the material produced at the previous IPC

• To our colleagues in our research group (Planning and Learning Group -- PLG) and very especially to Daniel Borrajo for all the encouragement and even for being in charge of some of our daily duties while we were working on the IPC

• Óscar Pérez, Jaime Pons, Roberto Fuentes and, in general, to the Laboratory of the Computer Science Department of the Universidad Carlos III de Madrid for their assistance in installing, configuring and maintaining the cluster

• Bharatranjan Kavuluri for submitting the Matchcellar domain

• Frédéric Maris for submitting the domains Cooking and Temporal Machine Shop

• Joerg Hoffmann and Hootan Nakhost for submitting the NoMystery domain

• Ron Petrick for submitting the Crisp domain

• Héctor Geffner and Nir Lipovetzky for submitting the Visit-All domain

• Amanda Coles and Andrew Coles for submitting the Market domain

• Héctor L. Palacios for suggesting the following domains that result from conformant planning: 1-dispose, dispose, grid, look-and-grab, push-to and classical

• Bhaskara Marthi for submitting the TidyBot domain

• Guy Shani for submitting the domains colorballs doors, medicalPKS150, medicalPKS199, sliding-doors, unix and wumpus

• Tomás de la Rosa for submitting the Floortile domain

• Derek Long for his support with the Automatic Validation Tool VAL

• Daniel L. Kovacs for providing a formal definition of PDDL 3.1