Last year IMLS issued a challenge around its Public Library Survey data as part of the inaugural National Day of Civic Hacking, June 1–2, 2013. With 11,000 participants nationwide, the event resulted in the creation of several IMLS-related projects, as well as greater awareness of library hackathon involvement throughout the country. Whether through hosted events or participation in local challenges, a number of libraries engaged in this nationwide open data event. Presenters share lessons learned from their involvement as well as practical tips for hosting your own library hackathon. Learn how libraries can add value to these events and reach new users for transformative results.