[ExpressionEngine](https://expressionengine.com/) is a mature, flexible, secure and free open-source content management system (CMS) written in PHP. Its source code is hosted on [Github](https://github.com/ExpressionEngine/ExpressionEngine). With ExpressionEngine, you can build full-featured websites, create a web app or serve content to mobile applications. All without requiring complex programming skills. This guide will walk you through the ExpressionEngine installation process on a fresh Ubu......