This document provides an overview of open source resources for libraries, including websites, slideshows, and articles about open source integrated library systems (ILS). It lists several popular open source ILS options like Evergreen, Koha, and OPALS, as well as resources for comparing systems and evaluating the costs and benefits of open source software. A number of articles are cited that discuss trends toward open source library management systems and case studies of libraries that have implemented open source ILS.