This document summarizes and discusses the research paper "ARC: A Self-tuning, Low Overhead Replacement Cache" by Nimrod Megiddo and Dharmendra Modha. It was published in USENIX FAST '03 and describes the Adaptive Replacement Cache (ARC) algorithm, which has been broadly deployed in production systems including ZFS, illumos, and FreeBSD. The document reviews the key ideas, related work, performance results reported in the paper and enhancements to ARC over time.