Alluxio is an open-source, memory-speed, virtual distributed storage system designed to bridge the gap between storage and computing by providing a unified namespace and enabling fast access to data across different storage systems. It was developed at UC Berkeley and has grown rapidly since its inception, offering flexibility, agility, and performance while managing tiered storage configurations. Common use cases include accelerating access to remote storage, sharing data at memory speed, and simplifying the integration of different storage systems.