This tutorial gives an overview of constraint programming and is organized in three main parts. The first part is a gentle introduction to constraint programming which reviews its basic principles and its overall architecture. The second part illustrates constraint programming on a variety of applications in resource allocation and scheduling, showing how constraint programming approaches the solving of complex combinatorial optimization problems. The last part reviews recent developments in constraint programming which aim at integrating constraint programming with integer programming or local search. These hybrid approaches exploit the synergies between these orthogonal technologies and represent promising directions for future research.