In just a few years, ESG, also known as sustainable or responsible investing, has moved from a slightly idealistic niche to front-page, a mainstream dimension for investors, one that strongly influences the performance and resilience of their investment over time. This is particularly the case in infrastructure, in view of its wide reaching and long-term consequences for the community. Indeed, in many cases private investors have been not just accompanying the trend but pioneering evolutions, complementing, or preceding regulatory requirements. A lot of corporates, investors and operators have embarked on communicating their values and sharing their approaches to the subject. It is thus only normal that the Long-Term Infrastructure Investors Association would devote a new, enriched edition of its Handbook to those latest developments. What sets aside this report from other compendiums is the rich variety of examples and illustrations drawn from our members collective experience, reflecting their specific challenges, the management practices, and proprietary methodologies they developed to manage and address them. It shows the appetite and inventiveness at play when it comes to developing bottom up solutions. It also makes a point towards the need to further consolidate and streamline tools and standards so as to be able to refer to commonly accepted market practices.