This book constitutes the thoroughly refereed post-proceedings of the 6th International Conference on Artificial Evolution, EA 2003, held in Marseilles, France in October 2003.

The 32 revised full papers presented were carefully selected and improved during two rounds of reviewing and revision. The papers are organized in topical sections on theoretical issues, algorithmic issues, applications, implementation issues, genetic programming, coevolution and agent systems, artificial life, and cellular automata.

The Arti?cial Evolution conference was originally conceived as a forum for the French-speaking Evolutionary Computation community, but has of late been acquiring an European audience, with several papers from Germany, Austria, Italy, Spain... However, AE remains as intended a small and friendly gathering, which will continue to be held every two years. Previous AE meets were held in Toulouse, Brest, and N ?mes. This year, the hosting was done by the LIL (Laboratoire d'Informatique du Littoral) in the not-so-cold city of Dunkerque. The invited talk on "Fitness Landscapes and Evolutionary Algorithms" was delivered by Colin Reeves of Coventry University This volume contains a selection of the papers presented at the conference. Twenty-seven papers were presented orally at the conference, selected from over 40 papers refereed by the program committee. After the conference, each p- sentation was reviewed and 20 papers were retained and revised for publication in this volume. The papers in this volume have been grouped into the following ?ve sections which more or less re?ect the organization of the oral presentations. 1. Invited Paper: C. Reeves brightly describes the state of the art in Fitness Landscapes.