The desktop of some platforms, such as Microsoft Windows, includes a system tray, as shown in the following screenshot:

On Microsoft Windows, it is called the "Taskbar Status Area." On Gnome, the "Notification Area", and on KDE, the "System Tray." However it may be called, the system tray is shared by all applications.

On platforms where it is supported, an application may insert a mini-icon, called a Tray Icon, into the system tray. This icon can be used to notify the user of a change in the application's status, or a need to take a particular action. Clicking the tray icon can bring up the application window. A popup menu and a tooltip can also be attached to the tray icon.

System tray support was added in version 6 of Java SE. For more information, see the New System Tray Functionality in Mustang article.