Sun Java lets you run programs like games, and other types of software within a website with Java apps. It is needed for many websites to use web chat, and shoutout boxes. Java is also used for desktop applications as well like file sharing clients, and word processors.
1. Go to Ubuntu Software Center on Applications menu on the Top left of Ubuntu top menu bar.
2. Type Java in the search box, and pick the Java Browser plugin which should be on the top of the list.
3. Install Java by using Ubuntu Software Center’s Install Wizard by clicking the install button.
4. Close all your browsers and restart them after the Java install.
Congrats, now you can run Java Applets on your Ubuntu 9.10 computer.