The Argonne Leadership Computing Facility (ALCF) is a national scientific user facility that provides supercomputing resources and expertise to the scientific and engineering community to accelerate the pace of discovery and innovation in a broad range of disciplines. As a key player in the nation’s efforts to deliver future exascale computing capabilities, the ALCF is also helping to advance scientific computing through a convergence of simulation, data science, and machine learning methods. ALCF computing resources are significantly more powerful than systems typically used for scientific research and are available to researchers from universities, industry, and government agencies. Through substantial awards of supercomputing time and user support services, the ALCF enables large-scale computing projects aimed at solving some of the world’s largest and most complex problems in science and engineering. Supported by the U.S. Department of Energy’s (DOE) Office of Science, Advanced Scientific Computing Research (ASCR) program, the ALCF is one of two DOE Leadership Computing Facilities in the nation dedicated to open science.