  In a recent paper, Krapivsky and Redner (Phys. Rev. E, 71 (2005) 036118)
proposed a new growing network model with new nodes being attached to a
randomly selected node, as well to all ancestors of the target node. The model
leads to a sparse graph with an average degree growing logarithmically with the
system size. Here we present compeling evidence for software networks being the
result of a similar class of growing dynamics. The predicted pattern of network
growth, as well as the stationary in- and out-degree distributions are
consistent with the model. Our results confirm the view of large-scale software
topology being generated through duplication-rewiring mechanisms. Implications
of these findings are outlined.
