The JDK 1.0.2 release does not support sound in applications. See Playing Sounds for information. Applets running within a Web browser can easily cause HTML documents to be displayed. This is supported with the AppletContext showDocument methods. See Communicating with the Browser for more information.
Applets can invoke public methods of other applets on the same page.
See Sending Messages to Other Applets On the Same Page for information. Although most applets stop running once you leave their page, they don't have to. Sometimes, however, it's appropriate for an applet to continue executing. For example, if a user tells an applet to perform a complex calculation, the user might want the calculation to continue. The user can then dismiss the window when it's no longer needed.