If I should mention one topic that has been more or less on everybody's lips at every conference I have attended in 2014, it would be Docker. I do not think I have ever seen a technology that has been embraced by so many so fast before.
So what is Docker then?
In short, it is a platform for building, shipping and running applications using containerization.
Read more about it at https://www.docker.com/whatisdocker/
Here are a couple of examples:
Get ubuntu images from Docker Hub:
$ docker pull ubuntu
Starting a container running Ubuntu 14.04 is as easy as this:
$ docker run -it ubuntu/14.04 /bin/bash
Deploying an application in a container running Wildfly on Ubuntu can be done by creating a Dockerfile similar to this (ivargrimstad/ubuntu-wildfly is a Docker image I have uploaded to my repository at Docker Hub (https://hub.docker.com/u/ivargrimstad/):
FROM ivargrimstad/ubuntu-wildfly ADD ./app.war /opt/jboss/wildfly/standalone/deployments/app.war
Build the image:
$ docker build --rm -t myapp .
And run the application on port 80:
$ docker run -it -p 80:8080 myapp
These were just a couple of easy examples to get you startet. Try the Docker tutorial at https://www.docker.com/tryit/ to try it out without installing anything locally.