Considered a key indicator of the progress and current state of the field, the TOP500 list has become a globally recognized tool for classifying technology trends in high-performance computing (HPC). This book provides the first comprehensive overview of the history, current trends, and future directions of the TOP500 list in particular and HPC in general. It explores the history of the list and HPC technology over the past two decades, reflecting on trends in computer architecture, parallelism, interconnect technology, processor technology, and operating systems that have shaped the field.