Policy-based computing is one of the tools that could be used to build self-managing systems (autonomic systems), these systems are able to manage themselves and dynamically readjusts in order to restore the balance in agreement between policies and business goals. Autonomic systems have mechanisms that allow them to monitor, regulate and control themselves, recovering from problems without recourse to human aid. This book titled "Policy -based Computing with Selinux", takes a look at current security situation of the Linux operating system and seek to address the challenges through policy based computing. The project was targeting a mechanism allowing flexible reconfiguration of the security mechanism of Linux operating system. The whole was based on research which deals with policy-based reconfiguration using Agile policies and Agile Lite library. C programming language was used to interact with the policies.