High-performance computing (HPC) involves using multiple interconnected computers combined with parallel processing approaches to solve problems that are too large or complex for a single computer. Generally, HPC systems, such as supercomputers and clusters, use high-bandwidth, low-latency network interconnects to enable fast and efficient communication across processes running on the HPC system. In geographic information science (GIScience), growth in data size and analytical complexity drive more demand for computing power and the need for HPC. Researchers and practitioners use HPC to process more geospatial data, run finer-grained simulations, and explore problems at spatial and temporal scales that were previously impossible. The key challenge in using HPC is coordinating and synchronizing dozens, hundreds, or thousands of processors simultaneously.