This document provides instructions for building Ring from source code on different platforms like Microsoft Windows, Ubuntu Linux, and MacOS X. It explains how to get the Ring source code by cloning its GitHub repository. It then lists the steps to build the Ring compiler, virtual machine, and various extensions like RingODBC, RingMySQL etc. on each platform. These steps include installing prerequisite libraries, generating source code for extensions that wrap third party libraries, and building/installing Ring and its components. The document also provides a brief overview of using CMake to build Ring and notes that libraries like MySQL client, OpenSSL, LibCurl, Allegro 5 and Qt need to be installed first before using CMake.