We'll be investigating a very powerful tool written in Java when we install DragMath in Chapter 7. There are many games and activities also written in Java. You'll need the correct version of the Java Runtime Environment (JRE) installed in order for the applets, as they are called, to work.
As a final thought for this chapter, there are plenty of games you can include in your Moodle course. Have you ever considered setting your students the exercise of creating their own online games? For example, both Sandfields Comprehensive (http://www.sandfields.co.uk) and ContentGenerator.net (http://contentgenerator.net) provide the facilities to allow you to create your own games. It is fun for your students (regardless of age), creative, and they may even get to learn some math along the way!