This program is designed to prank whoever runs it by quickly opening and closing many windows, which do not terminate when a single window is closed. To end the program once it has been run, a person would need to use a system tool to manually end the task.
Ideally this program would be exported into a .jar file and given a seemingly innocuous name, such as Minecraft.jar, to entice an unknowing victim to run the program. Or just added to list of things to execute on system startup.
An example of such a file can be found for running in out/Minecraft.jar