In this report, we investigate which technologies are utilised in augmented reality (AR) and virtual reality (VR) development projects. In the first chapter, we look at the broad umbrella of technologies used by AR and VR practitioners, examining usage by which of the two development areas they’re involved in as well as other demographic data. In chapter two, we dive deeper into these technologies, understanding how usage changes based on what kinds of experiences developers are building. Chapter three takes a closer look at the platforms used by AR and VR practitioners as well as how the most important goals in AR and VR development shape AR and VR practitioners’ choice of platform to use. Finally, chapter four investigates which SDKs are used in AR and VR development projects, which coding languages are used, and which design tools are used.