[de] Most empirical studies on the evolution and quality of libre software focus on individual software projects. Instead, we aim to empirically study, analyse and compare software distributions. We focus on libre software distributions and follow an ecosystem and GQM-based approach. As a pilot case, we use and analyse package-related metrics for Debian and Ubuntu using data extracted from the Ultimate Debian Database (UDD). These metrics allow us to analyse and understand the co-evolution of these two libre software distributions. In particular, we are interested in how the sharing of packages between Ubuntu and Debian a??ects the quality of these packages. We observed an increasing amount of sharing between both projects' communities since the establishment of the Ubuntu project, in 2004.
