In August 2007, the International Linear Collider published a Reference Design Report. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D programme, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.