This book is a collection of 16 papers written by students and collaborators of Jerzy Tiuryn, to whom the book is dedicated on the occasion of his 60th birthday. Tiuryn's scientific work spans two centuries and can be broadly divided into two sections. In the 20th century, he contributed greatly to the theory of Hoare logic and various other dynamic logics, especially first-order dynamic logic, before turning his attention towards functional programming, type-inference and lambda calculus. With the advent of the 21st century, Tiuryn turned his attention to work which contemplates the beauty of life and the origin of human complexity, including molecular sequence analysis, protein folding and the extremely complex and intriguing process of gene regulation, as well as molecular evolution and phylogenetics. In the course of his career, Tiuryn has been an inspiring teacher and collaborator to some 13 PhD students and 40 co-authors. The contributions presented here fittingly reflect the variety and breadth of Tiuryn's own work and achievements in their diversity and style.