Hybrid Metaheuristic for the Assembly Line Worker Assignment and Balancing Problem -- An ELSxPath Relinking Hybrid for the Periodic Location-Routing Problem -- Hybridizing Beam-ACO with Constraint Programming for Single Machine Job Scheduling -- Multiple Variable Neighborhood Search Enriched with ILP Techniques for the Periodic Vehicle Routing Problem with Time Windows -- A Hybridization of Electromagnetic-Like Mechanism and Great Deluge for Examination Timetabling Problems -- Iterative Relaxation-Based Heuristics for the Multiple-choice Multidimensional Knapsack Problem -- Solving a Video-Server Load Re-Balancing Problem by Mixed Integer Programming and Hybrid Variable Neighborhood Search -- Effective Hybrid Stochastic Local Search Algorithms for Biobjective Permutation Flowshop Scheduling -- Hierarchical Iterated Local Search for the Quadratic Assignment Problem -- Incorporating Tabu Search Principles into ACO Algorithms -- A Hybrid Solver for Large Neighborhood Search: Mixing Gecode and EasyLocal ?+?+? -- Multi-neighborhood Local Search for the Patient Admission Problem -- Matheuristics: Optimization, Simulation and Control.

This book constitutes the refereed proceedings of the 6th International Workshop on Hybrid Metaheuristics, HM 2009, held in Udine, Italy, in October 2009. The 12 revised full papers presented together with one invited talk were carefully reviewed and selected from 22 submissions. The papers discuss current issues of combinations of metaheuristics and other solving techniques of universal concern such as novel combinations of components from different metaheuristics, hybridization of metaheuristics and AI/OR techniques, low-level hybridization, high-level hybridization, portfolio techniques, expert systems, cooperative search, automated parameter tuning, empirical and statistical comparison, theoretical aspects of hybridization, parallelization, and software libraries.