Hacktoberfest is an annual global hackathon event celebrating open source software hosted by DigitalOcean in partnership with GitHub. The event was created to raise awareness for the open source community and encourage participation in open source projects. Participants are challenged to contribute a specific amount of pull requests during the month of October to public open source repositories on GitHub in order to earn a limited-edition T-shirt and swag from the host and sponsors. In 2018, the number of pull requests necessary to receive a T-shirt was raised from 4 to 5 and Twilio joined as a sponsor.