  The widespread use of GitHub among software developers as a communal platform
for coordinating software development has led to an abundant supply of publicly
accessible data. Ever since the inception of Bitcoin, blockchain teams have
incorporated the concept of open source code as a fundamental principle, thus
making the majority of blockchain-based projects' code and version control data
available for analysis. We define health in open source software projects to be
a combination of the concepts of sustainability, robustness, and niche
occupation. Sustainability is further divided into interest and engagement.
This work uses exploratory factor analysis to identify latent constructs that
are representative of general public interest or popularity in software, and
software robustness within open source blockchain projects. We find that
interest is a combination of stars, forks, and text mentions in the GitHub
repository, while a second factor for robustness is composed of a criticality
score, time since last updated, numerical rank, and geographic distribution.
Cross validation of the dataset is carried out with good support for the model.
A structural model of software health is proposed such that general interest
positively influences developer engagement, which, in turn, positively predicts
software robustness. The implications of structural equation modelling in the
context of software engineering and next steps are discussed.
