Fractal Figures: Visualizing Development Effort for CVS Entities

Versioning systems such as CVS or Subversion exhibit a large potential to investigate the evolution of software systems. They are used to record the development steps of software systems as they make it possible to reconstruct the whole evolution of single files. However, they provide no good means to understand how much a certain file has been changed over time and by whom. In this paper we present an approach to visualize files using fractal figures, which: (1) convey the overall development effort; (2) illustrate the distribution of the effort among various developers; and (3) allow files to be categorized in terms of the distribution of the effort following gestah principles. Our approach allows us to discover files of high development efforts in terms of team size and effort intensity of individual developers. The visualizations allow an analyst or a project manager to get first insights into team structures and code ownership principles. We have analyzed Mozilla as a case study and we show some of the recovered team development patterns in this paper as a validation of our approach