This page is a work in progress... apologies to all...
jEdit is the (free) editor Alexa uses in class. It's nice because it runs on all platforms, and supports things like syntax-highlighting. Did I mention it's free? If you'd like to get it working at home, the first thing you should do is go to jEdit's website.
On the Mac OS X, you shouldn't have to do anything else. In particular, you should not have to download Java or a terminal window or anything else.
The following instructions were very kindly provided by Kiron Roy.
Links to download jEdit and Sun Java SE:
This is important!! When Installing Java SE, make sure the path name has no spaces in it. For instance, Do NOT install it in C:\Program Files\Java\jdk... This will cause problems when you try to compile or run programs because windows is silly. REMEMBER WHERE YOU INSTALL JAVA SE!!!
Click Start-->Run Then type in cmd. If you are on windows Vista, you can search for run in the search bar.
You should get a black box called the command prompt. This is like the Unix/Linux/Mac Terminal. Get to the directory you want by typing cd <path> without the angle brackets. Once you're in the directory you want to save your Java Programs, type jedit <filename>.java &. This will open up a jEdit Java File with all the pretty colors.
Go back to the command prompt and make sure you're in the correct directory (you can check that your file is there by typing dir). I hope you remembered where you installed Java SE. If not, then search for javac.exe. Find the path for javac.exe and type that into the command prompt followed by <filename>.java
So, to do this, go to Control Panel-->System-->Advanced System Settings-->Environmental Variable. Then add your path to both User Variables and System Variables. Do this by clicking add, typing a variable name and then typing the path of javac.exe and java.exe (This should be the same path, so you only need to add one variable to both the User Variables and System Variables).
If this has been helpful to you (or even if it hasn't), thank Kiron Roy for taking the time (and frustration, I can only imagine) to figure this all out.