24 Pull Requests is an annual initiative that encourages developers to contribute to open source projects during the holiday season by submitting 24 pull requests between December 1 and December 24. Last year, nearly 3,000 developers participated, contributing to over 6,000 open source projects. The 24 Pull Requests web app provides information about the event, helps developers find projects in need, and visualizes their contributions on a calendar. Participants can contribute in various ways, such as fixing bugs or adding documentation, by signing in with their GitHub accounts to track their contributions. The event is promoted by Lee Reilly, a Senior Program Manager at GitHub, known for supporting developer communities and organizing hackathons and game jams.