The Triple Bottom Line Tool is a web-based platform designed to help investors, decision-makers, and economic development professionals enhance investment performance by better accounting for impact on a broad array of economic, environmental, and social factors – what’s referred to as the triple bottom line or TBL. The casebook was created as a companion to the Triple Bottom Line Tool (TBL Tool) in order to help illustrate what triple bottom line economic development may look like in practice and share lessons learned.