Structural crystallography is often thought to be synonymous with single-crystal crystallography, yet for several decades, powder diffraction has made important contributions to the understanding of materials structure and behaviour. However, it is perhaps the last decade that has seen some of the most remarkable breakthroughs in experimental powder diffraction and in the analysis of powder diffraction data, to the extent that it is no longer considered to be an analytical technique of last resort. Instrumentation at both the laboratory and facility level has become increasingly versatile to the extent that throughput and resolution are no longer mutually exclusive. In the field of data analysis, ingenious algorithms that take full advantage of modern computing power have meant that inorganic, molecular and even protein structures are being solved and refined relatively routinely. The 44th crystallographic course at the Ettore Majorana Centre was intended to serve as a complete introduction to the diverse field of powder diffraction, and to provide a firm grounding for attendees, from which to build future research achievements. The photographer is Peter Müller.