XScreenSaver

XScreenSaver packages installed on my mac mini (obtained with apt list --installed | grep xscreensaver)

xscreensaver-data-extra/focal,now 5.42+dfsg1-1ubuntu1 amd64 [installed]
xscreensaver-data/focal,now 5.42+dfsg1-1ubuntu1 amd64 [installed]
xscreensaver-gl-extra/focal,now 5.42+dfsg1-1ubuntu1 amd64 [installed]
xscreensaver-gl/focal,now 5.42+dfsg1-1ubuntu1 amd64 [installed,automatic]
xscreensaver/focal,now 5.42+dfsg1-1ubuntu1 amd64 [installed]

Installation Steps

apt install xscreensaver
apt install xscreensaver-data-extra
apt install xscreensaver-gl
apt install xscreensaver-gl-extra

# This might not be needed?
gsettings set org.cinnamon.desktop.session idle-delay 0

cp /usr/share/xscreensaver/xscreensaver-daemon.desktop ~/.config/autostart

Security

The XScreenSaver docs suggest configuring some things to make the lock screen more robust: https://www.jwz.org/xscreensaver/man1.html

• Disable ctrl-alt-backspace to kill the X server
• Disable ctrl-alt-F1 etc. to switch virtual terminals