The document discusses the benefits of open source software over proprietary software for government agencies. It outlines some of the technical constraints and risks of proprietary software, including high licensing costs and lack of flexibility. It then details how the Greater London Authority built support for open source by identifying influencers, focusing on business benefits like cost savings, and establishing an open source and cloud first strategy. Key aspects of their implementation included building foundations with open source tools like Apache, Linux, Tomcat, and Drupal, and creating an open data store to provide datasets freely and encourage application development using the data.