  GitHub, renowned for facilitating collaborative code version control and
software production in software teams, expanded its services in 2017 by
introducing GitHub Marketplace. This online platform hosts automation tools to
assist developers with the production of their GitHub-hosted projects, and it
has become a valuable source of information on the tools used in the Open
Source Software (OSS) community. In this exploratory study, we introduce GitHub
Marketplace as a software marketplace by comprehensively exploring the
platform's characteristics, features, and policies and identifying common
themes in production automation. Further, we explore popular tools among
practitioners and researchers and highlight disparities in the approach to
these tools between industry and academia. We adopted the conceptual framework
of software app stores from previous studies to examine 8,318 automated
production tools (440 Apps and 7,878 Actions) across 32 categories on GitHub
Marketplace. We explored and described the policies of this marketplace as a
unique platform where developers share production tools for the use of other
developers. Furthermore, we systematically mapped 515 research papers published
from 2000 to 2021 and compared open-source academic production tools with those
available in the marketplace. We found that although some of the automation
topics in literature are widely used in practice, they have yet to align with
the state of practice for automated production. We discovered that
practitioners often use automation tools for tasks like "Continuous
Integration" and "Utilities," while researchers tend to focus more on "Code
Quality" and "Testing". Our study illuminates the landscape of open-source
tools for automation production in industry and research.
