The Essence of Computation : Complexity Analysis Transformation By presenting state of the art aspects of the theory of computation this book commemorates the 60th birthday of Neil D. Jones whose scientific career parallels the evolution of computation theory itself. The 20 reviewed research papers presented together with a brief survey of the work of Neil D. Jones were written by scientists who have worked with him in the roles of student colleague and in one case mentor. In accordance with the Festschrifts subtitle the papers are organized in parts on computational complexity program analysis and program transformation