If you scroll down, there is a link to the source on the webpage itself.
Just press ctrl+F, copy this text:
A ZIP archive with the source code can be found here.
and paste it in. Then click on "here". Download the zip file, and you're good to go! Click on Index to run the program by itself.
Want to see how they made the HTML file? Right click on "index", click open with, click on Notepad, and uncheck "Use this as default program" then click OK. Now you're looking at the source code.
Using the same method, you can check out the Java files in the js folder.
I also suggest downloading Notepad++ [http://notepad-plus-plus.org/] for free if you are going to be editing these files. It is a more powerful text editor meant for code, and it organizes different code into colours for you. It also has a ton of other features that I'm not quite sure about.
