As computer science enters the new millennium methods and languages for reasoning with
constraints have come to play an important role with both t- oretical advances and practical
applications. Constraints have emerged as the basis of a representational and computational
paradigm that draws from many disciplinesandcanbebroughttobearonmanyproblemdomains includingar-
?cial intelligence databases and combinatorial optimization. The conference is concerned with
all aspects of computing with constraints including algorithms applications environments
languages models and systems. The Sixth InternationalConference on Principles and Practiceof
Constraint Programming (CP2000) continues to provide an international forum for p- senting and
discussing state-of-the-art research and applications involving c-
straints.Afterafewannualworkshops CP 95tookplaceinCassis France CP 96 in Cambridge USA CP 97
in Schloss Hagenberg Austria CP 98 in Pisa Italy and CP 99 in Alexandria USA. This year the
conference is held in Singapore from 18 through 21 September 2000. This volume comprises the
papers that were accepted for presentation at CP2000.From the 101 papersthat were submitted 31
papers wereaccepted for presentation in the plenary session and 13 papers were selected as
posters and have a short version (?ve pages) in this volume. All papers were subjected to
rigorous review three program committee members (or their designated revi- ers) refereed each
paper. Decisions were reached following discussions among reviewers and in some instances by
e-mail consultation of the entire program
committee.Ibelievethereaderwill?ndthesearticlestobeofthehighestquality representing a
signi?cant contribution to the ?eld.
