Here is a Pyqt5 panel that shows opened windows. Written with less than 50 lines of code for Linux.
Notice. This panel is meant to be transparent. Install xcompmgr, compiz etc.
License: PanelX v.0.1 Copyright (c) 2020 JJ Posti This program comes with ABSOLUTELY NO WARRANTY For details see: http://www.gnu.org/copyleft/gpl.html. This is free software, and you are welcome to redistribute it under GPL Version 2, June 1991″)
Dependencies(packages may be different depending on distribution):