This document provides an overview of Tachyon, an open-source memory-centric distributed storage system. It discusses Tachyon's motivation of leveraging faster memory storage, architecture that manages data across tiers of storage, and status as an Apache project used in production at over 50 companies. The document outlines Tachyon's ability to improve data sharing and fault tolerance across different compute frameworks. It shares several customer use cases and previews new features around lineage and tiered storage. The overall goal of Tachyon is to better assist other components with distributed memory-centric storage.