This exercise was conceived as a way to show students the importance of good programming style by making them deal directly with the problems created by poorly-written code.
Several files on this page are in Adobe's Portable Document Format. Some systems come with programs which can read PDF files; if yours did not, you can almost certainly find a version of Adobe Acrobat which will work on your machine.
This link will take you to Adobe's page for Acrobat.
You probably want to click on the "Adobe Reader" link,
and then look under "Downloads" for "Free Adobe Reader".