  When inspiring software developers to contribute to open source software, the
act is often referenced as an opportunity to build tools to support the
developer community. However, that is not the only charge that propels
contributions -- growing interest in open source has also been attributed to
software developers deciding to use their technical skills to benefit a common
societal good. To understand how developers identify these projects, their
motivations for contributing, and challenges they face, we conducted 21
semi-structured interviews with OSS for Social Good (OSS4SG) contributors. From
our interview analysis, we identified themes of contribution styles that we
wanted to understand at scale by deploying a survey to over 5765 OSS and Open
Source Software for Social Good contributors. From our quantitative analysis of
517 responses, we find that the majority of contributors demonstrate a
distinction between OSS4SG and OSS. Likewise, contributors described
definitions based on what societal issue the project was to mitigate and who
the outcomes of the project were going to benefit. In addition, we find that
OSS4SG contributors focus less on benefiting themselves by padding their resume
with new technology skills and are more interested in leaving their mark on
society at statistically significant levels. We also find that OSS4SG
contributors evaluate the owners of the project significantly more than OSS
contributors. These findings inform implications to help contributors identify
high societal impact projects, help project maintainers reduce barriers to
entry, and help organizations understand why contributors are drawn to these
projects to sustain active participation.
