I’m on Kubuntu 24.04 and I got xscreensaver working in Wayland.

You have to log into an X11 session first and set up xscreensaver how you want it. Once it’s set up and working, log out of the X11 session and log back into the Wayland session.

Go to the System Settings and look for Autostart. Make an autostart entry for xscreensaver here. Then check the xscreensaver.desktop file that created and make sure it looks like this:

[Desktop Entry]
Comment[en_US]=
Comment=
Exec=xscreensaver --no-splash
GenericName[en_US]=
GenericName=
Icon=xscreensaver
MimeType=
Name[en_US]=XScreenSaver
Name=XScreenSaver
Path=
StartupNotify=true
Terminal=false
TerminalOptions=
Type=Application
X-KDE-SubstituteUID=false
X-KDE-Username=
X-Ubuntu-Gettext-Domain=xscreensaver

As long as this is set to autostart, you will have a working xscreensaver in Kubuntu, if nothing else. I cannot confirm it working on any other systems and you absolutely do need both X11 and Wayland as sign in options for this to work. If you want to change settings you will have to switch back to X11 or I use scripts to edit the .xscreensaver configuration file.

For example I wrote two small python scripts for changing the length of time before the screen saver activates, and use cron to run them in the morning and evening. This is the one for the morning:

import os
import sys
import fileinput

# Read in the file
with open('.xscreensaver', 'r') as file:
  filedata = file.read()

# Replace the target string
filedata = filedata.replace('timeout:	0:05:00', 'timeout:	1:00:00')

# Write the file out again
with open('.xscreensaver', 'w') as file:
  file.write(filedata)

The morning script changes the timeout to five minutes, and the evening script changes is to an hour, making it a simple find and replace a string for both since we’re just rotating numbers.

and this is what it would look like in your crontab:

0 7 * * * python3 /home/yourusername/screensavermorning.py