DigitalOcean's Hacktoberfest is an annual event celebrating open source software, where participants can earn a T-shirt by making four pull requests to any public GitHub repository within October. A suggested project is building a Hacktoberfest Checker app using the Bottle web framework, which allows users to track their progress towards the T-shirt goal. This app retrieves pull requests via the GitHub API, displays progress, and can optionally include a GitHub login for automatic user retrieval. Participants are encouraged to contribute their projects to the community branch of the Challenges repository, which also counts towards the Hacktoberfest goal. The initiative aims to teach Python through community-driven exercises, fostering a collaborative learning environment.