Java is a full-grown programming language that can be used on web pages that can be used to create mini-programs called applets. These can produce a variety of special effects, such as animations. They can be used to interact with the user through a graphical user interface (GUI). Java also includes some powerful imaging functions, that can be used to apply a variety of filter effects to images, such as blurring, sharpening or smoothing.
Here are some examples of Java applets. You will need a Java-enabled web browser in order to view them.