Extensible nature

As mentioned earlier, WildFly's default distribution is a Java EE application server with all necessary libraries. Owing to the extensible nature of WildFly, you can easily create your own server distribution. It is possible to trim unused subsystems; a good example here may be the web profile, which contains only those subsystems that are needed to serve web pages and may be treated as a web server. It is also easy to add your own extensions to provide additional functions.

As you will learn later in this book, Swarm takes advantage of a great detail from both of these abilities, automatically trimming the server so that it uses only the libraries needed by your service, and also provides a bunch of microservices-dedicated extensions.