  We conduct an exploratory, large-scale, longitudinal study of 50 years of
commits to publicly available version control system repositories, in order to
characterize the geographic diversity of contributors to public code and its
evolution over time. We analyze in total 2.2 billion commits collected by
Software Heritage from 160 million projects and authored by 43 million authors
during the 1971-2021 time period. We geolocate developers to 12 world regions
derived from the United Nation geoscheme, using as signals email top-level
domains, author names compared with names distributions around the world, and
UTC offsets mined from commit metadata.We find evidence of the early dominance
of North America in open source software, later joined by Europe. After that
period, the geographic diversity in public code has been constantly increasing.
We also identify relevant historical shifts related to the UNIX wars, the
increase of coding literacy in Central and South Asia, and broader phenomena
like colonialism and people movement across countries (immigration/emigration).
