Constitutes the refereed proceedings of the 9th European Conference on Genetic Programming, EuroGP 2006, held in Budapest, Hungary, in April 2006, collocated with EvoCOP 2006. This book features the papers that address fundamental and theoretical issues, along with a variety of papers dealing with different application areas.

802.11 De-authentication Attack Detection Using Genetic Programming.- 802.11 De-authentication Attack Detection Using Genetic Programming.- A Divide & Conquer Strategy for Improving Efficiency and Probability of Success in Genetic Programming.- A Genetic Programming Approach to Solomonoff’s Probabilistic Induction.- A Less Destructive, Context-Aware Crossover Operator for GP.- AQUAGP: Approximate QUery Answers Using Genetic Programming.- Blindbuilder: A New Encoding to Evolve Lego-Like Structures.- Dynamic Scheduling with Genetic Programming.- Emergent Generality of Adapted Locomotion Gaits of Simulated Snake-Like Robot.- Evolving Crossover Operators for Function Optimization.- Genetic Programming, Validation Sets, and Parsimony Pressure.- Geometric Crossover for Biological Sequences.- Incentive Method to Handle Constraints in Evolutionary Algorithms with a Case Study.- Iterative Filter Generation Using Genetic Programming.- Iterative Prototype Optimisation with Evolved Improvement Steps.- Learning Recursive Functions with Object Oriented Genetic Programming.- Negative Slope Coefficient: A Measure to Characterize Genetic Programming Fitness Landscapes.- Population Clustering in Genetic Programming.- Projecting Financial Data Using Genetic Programming in Classification and Regression Tasks.- Solving Sudoku with the GAuGE System.- The Halting Probability in Von Neumann Architectures.- Using Subtree Crossover Distance to Investigate Genetic Programming Dynamics.- Posters.- Characterizing Diversity in Genetic Programming.- Complexity and Cartesian Genetic Programming.- Design of Robust Communication Systems Using Genetic Algorithms.- Developmental Evaluation in Genetic Programming: The Preliminary Results.- Evolving Noisy Oscillatory Dynamics in Genetic RegulatoryNetworks.- Information-Dependent Switching of Identification Criteria in a Genetic Programming System for System Identification.- Invariance of Function Complexity Under Primitive Recursive Functions.- On the Locality of Grammatical Evolution.- Optimizing the Initialization of Dynamic Decision Heuristics in DPLL SAT Solvers Using Genetic Programming.- P-CAGE: An Environment for Evolutionary Computation in Peer-to-Peer Systems.- Positional Independence and Recombination in Cartesian Genetic Programming.