for questions about creating a tray icon for a software application, customising the behaviour of a tray icon, and adding application control or monitoring to a tray icon. For questions which relate the system notification area or system tray in general, use the notification-area or system-tray tag instead.
About trayicon
A tray icon is a small, graphical, interactive icon which remains available in the notification-area of a graphical desktop environment such as windows, osx, gnome, and kde, to allow for convenient control, monitoring and/or termination of a running software application.
In desktop environments that support a notification area, the area is easily accessible and always visible, so that tray icons and important notices can be seen immediately. For example, in Windows XP and in KDE 4, the system notification area is nestled alongside the clock on the main taskbar. The system notification area is often known as the system tray, though this is a misnomer.
Tray icons may be permanently visible in the system notification area, or the desktop environment may allow automatic or manual hiding of tray icons which belong to applications which are currently inactive or rarely used.