These links may or may not work for you.
Java is a very powerful programming language. It was designed for the internet. It will run on any machine, any operating system. Most programs will only run on one kind of machine and one operating system. Java was so good that Microsoft made it not work in Widows. If you don't have a Java Virtual Machine on your computer these applets will not work for you.
You can get the Java Virtual Machine Plug-in free from Sun. Be sure to read the instructions.