  Context: Over the last decades, open-source software has pervaded the
software industry and has become one of the key pillars in software
engineering. The incomparable growth of open source reflected that pervasion:
Prior work described open source as a whole to be growing linearly,
polynomially, or even exponentially.
  Objective: In this study, we explore the long-term growth of open source and
corroborating previous findings by replicating previous studies on measuring
the growth of open source projects.
  Method: We replicate four existing measurements on the growth of open source
on a sample of 172,833 open-source projects using Open Hub as the measurement
system: We analyzed lines of code, commits, new projects, and the number of
open-source contributors over the last 30 years in the known open-source
universe.
  Results: We found growth of open source to be exhausted: After an initial
exponential growth, all measurements show a monotonic downwards trend since its
peak in 2013. None of the existing growth models could stand the test of time.
  Conclusion: Our results raise more questions on the growth of open source and
the representativeness of Open Hub as a proxy for describing open source. We
discuss multiple interpretations for our observations and encourage further
research using alternative data sets.
