Effective and Efficient Reuse with Software Libraries

icht und durch die Fakultät für Informatik am 20.11.2012 angenommen. Research in software engineering has shown that software reuse positively affects the competitive-ness of an organization: the productivity of the development team is increased, the time-to-market is reduced, and the overall quality of the resulting software is improved. Today’s code repositories on the Internet provide a large number of reusable software libraries with a variety of functionality. To analyze how software projects utilize these libraries, this thesis contributes an empirical study on the extent and nature of software reuse in practice. The study results indicate that third-party code reuse plays a central role in modern software development and that reuse of software libraries is the predominant form of reuse. It shows that many of today’s software systems consist to a considerable fraction of code reused from software libraries. While these libraries represent a great reuse opportunity, they also pose a great challenge to de-velopers. Often these libraries and their application programming interfaces (APIs) are large and complex, leading to cognitive barriers for developers. These obstacles can cause unintended reim-plementation in a software system. This negatively affects the system’s maintainability due to th