I'm new here: brand new to the forums and to the world of Java programming and Xcode, and I have some questions that have not been answered by countless searches on developer.apple.com or google: Evidently Xcode includes a JDK and JRE, but I don't know how to use either. How do I compile/run a short, simple program like the classic "Hello, world!" one? I have the code written in a text editor, but I don't know how to use Xcode with it. Thanks! Edit: I'm running 10.5.2 with Java upgraded to 1.6 on a 2.2 Ghz Macbook.