This document discusses the Government Digital Service's approach to open source software. It notes that in 2012, GOV.UK was first launched and by 2016, much of the government's code was openly accessible. The key aspects of the GDS's open source approach are using existing open source software, contributing to open source projects, and openly publishing their own code. The document outlines several benefits of this approach, including improved code quality, increased collaboration, and greater transparency around government technology work. It also acknowledges some challenges of open source like security risks but argues that open source overall helps make government more digital by default.