Multi-view environments provide different views of software systems optimized for different stakeholders. One way of ensuring consistency of overlapping and inter-dependent information contained in such views is to project them “on demand” from a Single Underlying Model (SUM). However, there are various ways of building and evolving such SUMs. This paper presents criteria to distinguish them, describes three archetypical approaches for building SUMs, and analyzes their advantages and disadvantages. From these criteria, guidelines for choosing which approach to use in specific application areas are derived.

S.111-112

Software maintenance and reengineering are vital software engineering activities for facilitating the evolution of large software systems. However, software maintenance is not only to be considered for existing systems, but also for new systems, where software models and artefacts evolve as part of iterative and incremental development processes. The Conference on Software Maintenance and Reengineering is the premier European forum to discuss the theory and practice of software maintenance, reengineering, and evolution of software systems. CSMR promotes fruitful discussion and exchange of experiences among researchers and practitioners about the development of maintainable systems, and their evolution, migration and reengineering. This special issue comprises extended versions of three papers, presented at CSMR 2008. The 12th CSMR focused on ‘Developing evolvable systems’. The need for systems to evolve in shorter timescales and with increased quality necessitates developing maintainable and evolvable systems. Defining, achieving, and assessing ‘evolvability’, as well as issues related to processes for developing evolvable software systems are open challenges. The CSMR 2008 technical program covered a wide range of current research activities in software maintenance and reengineering, as well as industrial and academic experience reports. It included keynote talks on future trends in Software Reengineering by John Mylopoulos (University of Toronto) on ‘Software Agents’ and by Jürgen Ebert (University of Koblenz-Landau) on the serious use of ‘Metamodels in Reengineering’. The topics on technical sessions showed the current trends in our field. These include: Supporting Evolution, Code Analysis, Reverse Engineering, Reengineering and Reuse, Aspect Orientation, and Ontologies. The program was complemented by tool demonstrations, industrial reports, a doctoral symposium, and four workshops. Papers were submitted from 26 countries covering all inhabited continents. Out of 87 submitted papers, 24 full papers were selected for presentation at CSMR 08. The authors of six selected papers, based on their suitability and quality as indicated by the reviewers, were invited to submit extended versions of their papers which went through a rigorous review process involving at least three reviewers. Eventually, three papers were selected for this special issue. Dynamic Update of Java Applications—Balancing Change Flexibility vs. Programming Transparency by Alan Gregersen and Bo Jørgensen deals with the dynamic change of software behaviour. The paper presents and discusses an approach to dynamically updating running Java applications while guaranteeing type and thread safety. Splitting a Large Software Repository for Easing Future Software Evolution—An Industrial Experience Report by Marco Glorie, Andy Zaidman, Arie van Deursen, and Lennart Hofland presents lessons learned in improving the maintainability of huge industrial software systems. The paper discusses the feasibility of using formal concept analysis and cluster analysis to split software repositories in industrial scale settings. An Evaluation of Code Similarity Identification for the Grow-and-Prune Model by Thilo Mende, Rainer Koschke, and Felix Beckwermert addresses incremental software evolution and quality improvement of software systems. This paper presents and evaluates the use of clone detection techniques and similarity measures to merge code clones which had originated in deliberated copying that requires additional refactoring.

The six articles in this special section are devoted to software language engineering.

In software engineering, the use of models and metamodeling approaches (e.g., MDA withMOF/UML) for purposes such as software design or software validation is an established practice. Ontologies constitute domain models formalized using expressive logic languages for class definitions and rules. Hence, when seen from an abstract point of view, the two paradigms and their various technological spaces seem closely related. However, in the state-of-the-art research and practice the two technologies are just beginning to converge and the relationship between the two is still under exploration. In this paper, we give an outline of current ontology technologies, such as the Semantic Web standards for a Web Ontology Language (OWL). Then, we describe a domain analysis of the different technical spaces, explaining the features of the different paradigms. Eventually, we describe some avenues for integrating various ontological technical spaces into metamodeling technical spaces.