The UK government issued a beta version of the Service Design Manual, stating guidelines on how to design digital services according to the Digital by Default Service Standard.
Setting a digital service standard is part of the Governmental Digital Strategy, which aims at producing public digital services, “so good, that people prefer to use them”.
The manual is an interesting reading in itself, but the Open Source section is a must.
Basically, the UK government is suggesting to use open source software for operating systems, networking software, web servers, databases and programming languages.
The choice is based on the quality of the overall development and maintenance process, not on economic grounds.