This is HelloWorld implemented in Java as an Eclipse project.
To download and modify it, open the git bash/shell program, navigate to your Eclipse
workspace of choice, and enter the command git clone https://github.com/Code-at-LTH/HelloWorld.git.
You can then open Eclipse and work on the project in that workspace.
If you wish to host your modifications on GitHub, you should fork it and clone that repo instead.