The best place to get the Java compiler is directly from Sun. Their website is http://java.sun.com although I assume you'd probably want to use an IDE for your computer science work. I use eclipse ( http://www.eclipse.org/ ) as it is my favorite IDE. You could also try Netbeans or JCreator, but I have little experience with these two applications so I couldn't help you if you had any problems. If you get an IDE, I'm fairly sure that it will install the javac compiler for you, but I could be wrong.