Emacs can use your GUI system taskbar to display a badge overlay on the Emacs taskbar icon, a progress bar report, and alert the user that an Emacs session needs attention. Note: The system taskbar might be called the dock, the launcher, or something similar.
On GNU/Linux eligible GUI desktops, system taskbar effects will appear on the desktop destinations determined by your shell extension, most often the application launcher or dock panel, or the top panel. Effects are global for an Emacs instance.
Note: The GNU/Linux implementation sends system taskbar messages to the GUI using D-Bus. You may need to install or configure shell extensions such as https://extensions.gnome.org/extension/307/dash-to-dock/ that implement Ubuntu’s Unity D-Bus launcher spec which you can read more about here https://wiki.ubuntu.com/Unity/LauncherAPI. See The D-Bus Manual.
On macOS/GNUstep 10.5+, system taskbar effects appear on the Dock and in the App Switcher. Effects are global for an Emacs instance. macOS/GNUstep need no special configuration.
On MS-Windows 7+, taskbar effects appear on the Windows system taskbar. Effects are associated with the frame from which they are initiated. MS-Windows needs no special configuration.
You must initialize system taskbar before using it. To do that, type M-x system-taskbar-mode.
The user option system-taskbar-use-progress-reporter integrates
system-taskbar-mode with Emacs progress report functions, which
many longer-running functions use to indicate the progress of their
work. Progress reports will appear in the echo area and on the system
taskbar Emacs icon. This variable defaults to t. Customize this
variable before enabling system-taskbar-mode. See (elisp)Progress
The user option system-taskbar-clear-attention-on-frame-focus
turns on a helper useful on GNU/Linux D-Bus platforms which
automatically clears the system taskbar attention indicator when any
Emacs frame is focused. This has no effect on macOS/GNUstep or
MS-Windows. It defaults to t. Customize this variable before
enabling system-taskbar-mode.
The user option system-taskbar-dbus-desktop-file-name helps
D-Bus on GNU/Linux identify launched instance of Emacs. It defaults to
‘emacsclient’ and may need to be changed to ‘emacs’ depending
on your GNU/Linux configuration.
The user option system-taskbar-dbus-timeout is a
troubleshooting tool and it likely does not need to be customized. It
defaults to nil which uses the D-Bus default timeout which is
25,000ms or 25s.
See System Taskbar in The Emacs Lisp Reference Manual