  Web-based hosting services for version control, such as GitHub, have made it
easier for people to develop, share, and donate money to software repositories.
In this paper, we study the use of Bitcoin to make donations to open source
repositories on GitHub. In particular, we analyze the amount and volume of
donations over time, in addition to its relationship to the age and popularity
of a repository.
  We scanned over three million repositories looking for donation addresses. We
then extracted and analyzed their transactions from Bitcoin's public
blockchain. Overall, we found a limited adoption of Bitcoin as a payment method
for receiving donations, with nearly 44 thousand deposits adding up to only 8.3
million dollars in the last 10 years. We also found weak positive correlation
between the amount of donations in dollars and the popularity of a repository,
with highest correlation (r=0.013) associated with number of forks.
