This document introduces uRequire, a tool that allows JavaScript code to be written once and run anywhere by converting code between different module systems and environments. It discusses the problems with existing module systems like AMD and CommonJS, and how uRequire addresses these issues by providing a unified module format and handling conversion, path resolution, and other complexities. The document explains uRequire's features like dependency management, code manipulation, build configurations, and declarative template options to customize module conversion and output.