This document provides an overview of the Kali Linux operating system. It describes Kali Linux as a Debian-based distribution aimed at advanced penetration testing and security auditing. It contains hundreds of tools for tasks like penetration testing, forensics, and reverse engineering. Kali Linux is developed and maintained by Offensive Security and was created as a rebuild of BackTrack Linux, with its first version releasing in 2013. It highlights some of Kali Linux's core developers and features, such as over 600 preinstalled applications, support for multiple languages and wireless devices, and flexibility in running on physical/virtual machines or mobile devices.