PrefaceThe 60th birthdays of Mario Coppo, Mariariangiola Dezani-Ciancaglini, and Simona Ronchi Della Rocca all fall between 2006 and 2007. These three researchers are widely known in the world community of theoretical computer scientists, and especially among the researchers in λ-calculus, type theory and semantics of programming languages. Owing to the significance of their contributions, the impact of their ideas and the large number of coworkers and students they have, we wish to honour them with the present collection of essays, covering most of their favourite topics, also showing how far the concepts and results originating from their works have gone.Our aim has been to illustrate both the past of the type assignment, the intersection types and the λ-calculus by presenting old results with new proofs in a new light; and to have a look at what is going on in these fields, since the original nucleus of the types for the λ-calculus has been widened encompassing object and process calculi, linear logic and implicit complexity.All of the present contributions have been invited, staring with a small group of coauthors of Coppo, Dezani and Ronchi. The number of papers has grown rapidly, as the news of our collection circulated, and other relevant themes were also suggested especially with regards to the most recent developments. The resulting collection is therefore the merit of the contributors, whose work has been submitted to a rigorous process of refereeing, and of the referees themselves, who provided criticism as well as suggestions to improve the papers. The absence of many researchers in the field is mostly casual, only due to the lack of space and to the poorness of our forces.Torino