Special issue on new ideas and emerging results in understanding software

Welcome to the special issue on new ideas and emerging results in understanding software. It is a present to Prof. Dr. Paul Klint on the occasion of his 65th birthday. His colleagues and friends who share similar research interests have written the papers, wanting to present Paul with a worthy gift. The initiative was taken by former PhD students of Paul, namely the guest editor, Mark van den Brand, Arie van Deursen, Frank Tip, and Eelco Visser. We would like to thank Jan Bergstra and Bas van Vlijmen for making this special issue possible and for their support. The topic of this issue, understanding software, is a continuation of the CWI Lectures on Understanding Software in 2012, Amsterdam. The drive to understand software complexity and the urge to simplify software construction are characteristics of the research, teaching and industrial work of Paul Klint. This broad topic is key, both from an academic and an industrial standpoint. Why does software fail? Why do software projects fail? How to understand and then fix broken software? How can we simplify software designs? It is ironic that the effectiveness of software systems – literal figments of our imagination – crumbles under our own cognitive limitations. These human limitations may be overcome by research in theory and technology of tools, enabling the next generation of innovative applications of computer programming. This special issue is divided into two sections, each approaching this topic from a different viewpoint. The first section is called "Software Construction": a collection of papers aiming to improve the development of new software and to improve the quality of the resulting software. The second section is called "Software Understanding": where tools are proposed to help understanding existing software systems, either in general or on a case-by-case basis. We have collectively written, reviewed and re-written 26 papers that identify new research directions, introduce provocative ideas, and propose new tools and new languages. Thank you Paul for having done the same in the past and we look forward to your future contributions to our field. Copyright © 2014 Elsevier B.V. All rights reserved.