This 5th issue contains a collection of 10 carefully selected and thorougly revised contributions. The articles deal with the following topics: web page language identification; a novel image edge detection approach using ant colony optimization techniques; component-based software development through the use of the agent paradigm; a method for integrating gene expression programming and cellular evolutionary algorithms; a model for selecting partners in a society, focussing on contextual fitness; a model for agent knowledge acquisition; methods of faulty video detection; a model for integrating the archival knowledge included in a user profile; a universal and formal description for agent systems; and a real-time and mulitilingual news event extraction system.