The 18^th EURO Summer/Winter Institute (ESWI XVIII) took place during the spring 2000 in Switzerland. The topic of ESWI XVIII, "Meta-heuristics in Combinatorial optimization", was selected due to its great current scientific interest: indeed, in recent years, several meta-heuristics have proved to be highly efficient for the solution of difficult combinatorial optimization problems. The Institute was focused more particularly on the development and the use of local search and population search algorithms. Applications of these meta-heuristics on academic or real life problems were also discussed.

This special issue of EJOR contains papers written by the participants to ESWI XVIII. These papers have benefited from fruitful discussions among the participants, the organizers and the invited speakers. We have tried to summarize here below some guidelines that should help in the design of successful adaptations of meta-heuristics to difficult combinatorial optimization problems.