What's a Tray Icon?

A Tray Icon is a small image that sits in your SystemTray, if you have one. Desktop Environments such as GNOME and KDE, as well as many standalone Window Managers?, have a SystemTray.

museeq >= 0.1.10 should have a Tray Icon, but this can be disabled at compile-time.
murmur also has a Tray Icon.