  Ever since the beginning of the outbreak of the COVID-19 pandemic,
researchers from interdisciplinary domains have worked together to fight
against the crisis. The open source community, plays a vital role in coping
with the pandemic which is inherently a collaborative process. Plenty of
COVID-19 related datasets, tools, software, deep learning models, are created
and shared in research communities with great efforts. However, COVID-19 themed
open source projects have not been systematically studied, and we are still
unaware how the open source community helps combat COVID-19 in practice. To
fill this void, in this paper, we take the first step to study COVID-19 themed
repositories in GitHub, one of the most popular collaborative platforms. We
have collected over 67K COVID-19 themed GitHub repositories till July 2020. We
then characterize them from a number of aspects and classify them into six
categories. We further investigate the contribution patterns of the
contributors, and development and maintenance patterns of the repositories.
This study sheds light on the promising direction of adopting open source
technologies and resources to rapidly tackle the worldwide public health
emergency in practice, and reveals existing challenges for improvement.
