Software plays an important role in determining the environmental impact of ICT products. It has a measurable impact on computer-hardware energy consumption and increasing requirements can make it necessary to replace computer hardware prematurely – a phenomenon known as software obsolescence. This Guide on Green Public Procurement of Software presents a set of criteria and proposes methods for implementation of these criteria for public tenders. The criteria can be applied to both commercially available standard software and to commissioning the development of software. This document is the translation of the 2019 German version, that has been revised in 2023.