To install any of the explorable digital environments click on the program and system you require. 
The software comes packaged as a zip file. Once downloaded unzip the file. If using a MAC locate and double click on the .app file. If using a PC locate and double click on the .exe file.
From the configuration panel select full screen or windowed, along with the desired resolution and quality   
If the program is not running smoothly try reducing the quality or resolution in the configuration panel.
Controls
Forwards: W
Backwards: S
Left: A
Right: D
Look: Mouse
Restart: R
Mouse sensitivity: X or Z
Invert mouse axis: I
Quit: Esc