The code on the cover of Hello World was taken from the webpages of the ACM "Hello World" project, which features approximately 204 different examples of Hello World code. This one was written in java by Danny Schales and can be found at http://www2.latech.edu/~acm/helloworld/java.html I was later told that the code we chose for the cover would not compile. I don't know java myself and so I have no idea, but I'm curious to know whether this is true. Please try it out and let me know.