This edited book contains articles accepted for presentation during the conference "Intelligent Information Systems 2005 (IIS 2005) - New Trends in Intelligent Information Processing and Web Mining" held in Gdansk, Poland, on June 13-16, 2005. Special attention is devoted to the newest developments in the areas of Artificial Immune Systems, Search engines, Computational Linguistics and Knowledge Discovery. The focus of this book is also on new computing paradigms including biologically motivated methods, quantum computing, DNA computing, advanced data analysis, new machine learning paradigms, reasoning technologies, natural language processing and new optimization techniques.