Type javac [codefile.java] to run the Java compiler.
Type java [ClassName] to run the VM. Note: You should NOT pass the VM a file with a .class or .java extension, just the name of the class that has a main method defined.
<APPLET CODE="HelloWorld.class" WIDTH=150 HEIGHT=25> This text is visible if the applet won't run! </APPLET>
That </APPLET> closing tag is real important. The text between the two will be displayed in non-Java-aware browsers.
If you wish to download the JDK to compile Java programs at home, head to this page to get the latest JDK (v1.2). I have said that we are using the 1.1.7 JDK in class, but I believe that the project you will be doing should be upwardly / backwardly / sidewardly compatible. It is probably a little unrealistic for me to believe this, but oh well.
Bear in mind that this is a 20meg download and not something you should take lightly. An overnight FTP might be your best bet if you've got a slow modem line. Alternatively, you could find some creative way to use bandwidth somewhere else and transport the files home on a Zip disk. Up to you. Just don't get in trouble for anything and blame it on me, 'K?