This document discusses the pros and cons of using open source software in libraries. It begins with an introduction to open source software and licenses. Popular open source software used in libraries are then outlined, including integrated library management systems (ILMS) like Koha and Evergreen, digital library software like DSpace and Greenstone, content management systems like Drupal and Joomla, and learning management systems like Moodle. The benefits of open source software for libraries are lower costs, easier licensing, better quality control through community involvement, customizability, and ample support resources. Potential drawbacks include less personal support, lack of training and expertise, need for technical skills to maintain the software, and lack of scalability in some cases. The