Hacktoberfest is an annual event, held every October, that encourages people to contribute to open-source software. It has been run by the cloud hosting company DigitalOcean since 2014, in some years with partners such as Major League Hacking and other sponsors. The event’s own site describes it as “a month-long celebration of open-source projects, their maintainers, and the entire community of contributors.” The basic mechanic is simple: participants who get a small number of qualifying pull requests accepted during the month earn a reward, historically a limited-edition T-shirt and later, in some years, the option to have a tree planted instead.
The appeal of Hacktoberfest is that it lowers the social barrier to a first contribution. For many developers, the first open-source pull request is intimidating, and a time-boxed event with a clear goal and a tangible prize gives newcomers a reason to push past that hesitation. Projects that want help often tag approachable tasks so that participants can find somewhere to start, which is why Hacktoberfest sits close to practices like the good first issue label and to the larger story of how the pull request opened up open-source contribution.
The same incentive that draws in newcomers also created the event’s defining crisis. In 2020 the reward structure produced a surge of low-effort and outright junk pull requests, as people raced to hit the threshold for a shirt by submitting trivial or meaningless changes. Maintainers of popular repositories were buried under spam: pull requests that fixed nothing, added whitespace, or edited a README for no real reason, each one demanding a maintainer’s time to triage and close. The phrase “Hacktoberfest spam” entered the open-source vocabulary that month, and some maintainers publicly asked to be excluded from the event entirely.
In response, the organizers reworked the rules. The most consequential change was a shift toward maintainer opt-in: rather than every public repository being fair game, projects had to signal participation, for example by applying a designated topic or label, so that pull requests counted only where maintainers actually wanted them. The rules also tightened the definition of a qualifying contribution, treating pull requests that were marked as spam or that were not accepted as invalid, and giving maintainers clearer tools to flag bad submissions. These reforms moved the event from a pure volume game toward something that tried to reward genuine, welcomed work.
Hacktoberfest endures as both a successful on-ramp and a cautionary tale. It has introduced a large number of people to their first contribution and helped many projects find new hands, while also demonstrating a general truth about incentives in open source: when you reward a countable proxy such as the number of merged pull requests, you get more of the proxy, not necessarily more of the value it was meant to stand for. The event’s later rules are best read as an ongoing attempt to keep those two things aligned.