Studying the evolution of open source systems at different levels of granularity: two case studies

This work presents a study of several evolutionary attributes of two open source software systems: the distributed file system Arla and the stable branch of the Web browser Mozilla. The attributes (size, activity rate and complexity) are visualized over releases using measures at various levels of granularity: folders, files and procedures. A number of hypotheses about the evolutionary behaviour of the systems are considered and, in general, supported by the data from the 2 systems.