Alkali activation is a highly active and rapidly developing field of activity in the global research and development community. Commercial-scale deployment of alkali-activated cements and concretes is now proceeding rapidly in multiple nations. This paper reviews the key developments in alkali-activated materials since 2011, with a particular focus on advances in characterisation techniques and structural understanding, binder precursors and activation approaches, durability testing and design, processing, and sustainability. The scientific and engineering developments described in this paper have underpinned the on-going scale-up activities. We also identify important needs for future research and development to support the optimal and appropriate utilisation of alkali activated materials as a component of a sustainable future construction materials industry. The contributions of JLP were supported by the European Research Council 7th Framework Programme, through the Starting Grant “GeopolyConc” (StG-335928), those of C. Shi were supported by the National Natural Science Foundation of China under contract Nos. U1305243 and 51378196.