Is it possible to install licensed software on Amazon EC2

Amazon EC2 essentially is just a platform for you to do what you want with it. You are given a choice of operating systems to use, which can be a Linux distribution, Windows Server or really anything you wish. After that, you are free to install whatever software you would install on your own servers. In reality, the only difference between an EC2 instance and running software on your own server is that Amazon hosts the server for you. Most of your day to day server operations will be exactly as if you owned the server yourself.