The document discusses promoting open source software in libraries. It notes financial pressures, a need for access to data and interoperability, and hidden libraries and archives as reasons for adopting open source in libraries. It acknowledges barriers including legacy systems and vendor oligopoly. Examples of successful open source library management systems, institutional repositories, discovery platforms, and linked open data projects are provided. Newer solo-developed projects from libraries and support structures like FOSS4Lib that help users are also mentioned.