Docker has versions for Mac, Windows, and many flavors of Linux at https://www.docker.com/community-edition#/download
Run the following commands:
$ docker run hello-world
$ docker pull ubuntu:14.04
$ docker pull nersc/ubuntu-mpi:14.04
Register for an account at https://cloud.docker.com/ (take note of your Docker ID and password). With docker installed, run
$ docker login -u <your docker ID>
and enter your password.
If you're using Linux or macOS,
you already have the ssh
client installed.
On Windows, install PuTTY
You can use http://play-with-docker.com/ to try Docker, but it won't work if all of us try it once! So use it only as a last resort, and it is up to you to not use any important information (like the Docker hub account) inside it.