I write a lot of my programs in Java. It's a nice language to program in, it's free, and probably most importantly, a program written in Java should run on just about any computer . The one drawback however is that you have to have Java installed on your PC first, and to be honest, it's a beast of a download. Although, with the rise in popularity of broadband internet connections, and the ongoing law suits against Microsoft, this is becoming less of an issue.

To run a program written in Java, you have to have a copy of the JVM (Java Virtual Machine) installed on your PC. The JVM comes in two flavours: the JRE (Java Runtime Environment), and the JDK (Java Developers Kit). The version you choose depends on what you want to be able to do with your java programs. If you just want to be able to use the programs, then you should download the JRE. If however you want to be able to modify the programs yourself, then you need the JDK, which is a bigger download.

Both the JRE, and the JDK can be found on the Sun Microsystems Website. Because both downloads are quite large (around 10 and 35 megabytes respectively), if you don't have the luxury of broadband, you may want to use a download manager such as GetRight to make the download less painful.

Once you have downloaded and installed your JVM, you should be ready to run Java programs, including those available on this site. If you should have any problems, you may also like to read the following: Setting up your computer for executable JAR files and Modifying your classpath.

If you plan to modify Java programs, once you have installed the JDK, all you need is a text editor such as Notepad (Windows) or Vi (Unix/Linux). However you may find it easier to use a development environment such as BlueJ which provides useful features such as syntax highlighting, project management and debugging.