An anonymous reader writes: ComputerWeekly reports that the U.K. government 'has, for the first time, mandated a preference for using open source software for future developments.' This comes from the newly released version of the Government Service Design Manual, which has a section about when government agencies should use open source. It says: 'Use open source software in preference to proprietary or closed source alternatives, in particular for operating systems, networking software, web servers, databases and programming languages.' The document also warns against vendor lock-in. This policy shift comes under the direction of government CTO Liam Maxwell, who said, 'In digital public services, open source software is clearly the way forward.' He added, 'We're not dogmatic about this – we'll always use the best tool for the job – but open source has major advantages for the public sector.'