The 10th International Conference on the Principles and Practice of Constraint Programming (CP 2003) was held in Toronto, Canada, during September 27 October 1, 2004. Information about the conference can be found on the Web at http: //ai.uwaterloo.ca/ cp2004/ Constraint programming (CP) is about problem modelling, problem solving, programming, optimization, software engineering, databases, visualization, user interfaces, and anything to do with satisfying complex constraints. It reaches into mathematics, operations research, arti?cial intelligence, algorithms, c- plexity, modelling and...