This document discusses WildFly Swarm, a tool that packages a Java application together with just the pieces of the WildFly application server runtime that it needs. It allows building self-contained applications that can run independently of any pre-installed server. The document outlines how WildFly Swarm works, how it allows selecting specific Java EE APIs and frameworks, and how it produces a single executable "uber jar" file. It also provides examples of creating a simple REST application using WildFly Swarm and customizing the runtime configuration.