I have an old desktop - PII 500 MHz - so had to install AntiX 7 on it. It will be a stand-a-lone computer for a small church library using tellico (a good program to manage different collections). I want the computer to automatically boot into AntiX, login as patron, and start up Tellico. When I want to add a new user, it asks for a password and won't let me add a user without a password. I have looked at slim.conf and see that there is a way to automatically login a user without a password. If I set slim up that way, does that bypass the password checking? TIA

No. It will allow auto login but the user still needs a password by default. Just make"patron" the default login and when you boot you will at"patron's" desktop. Just make the files associated with tellico owned by another user with only read permission and it should work fine. You can su to another user to make changes.

I have set up three users - myself, libstaff & library. And I have changed slim.conf to have library the default login. Library shows as the default login, but any of the three users can login.
Q1: It asks for the password for all three users. How or what do I need to change to allow library to login without a password?
Q2: The only user who can shutdown is myself. What do I set to allow any user to shutdown?
Q3: I see from the slim handbook that upon login, I can tell it to run a certain program. Can that be for just one user or is it for all users?
My slim.conf file is:

# Path, X server and arguments (if needed)
# Note: -xauth $authfile is automatically appended
default_path ./:/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
default_xserver /usr/X11R6/bin/X
xserver_arguments -dpi 96 -nolisten tcp

# Commands for halt, login, etc.
halt_cmd /sbin/shutdown -h now
reboot_cmd /sbin/shutdown -r now
console_cmd /usr/X11R6/bin/xterm -C -fg white -bg black +sb -T"Console login" -e /bin/sh -c"/bin/cat /etc/issue; exec /bin/login"
#suspend_cmd /usr/sbin/suspend

# Full path to the xauth binary
xauth_path /usr/X11R6/bin/xauth

# Xauth file for server
authfile /var/run/slim.auth


# Activate numlock when slim starts. Valid values: on|off
numlock on

# Hide the mouse cursor (note: does not work with some WMs).
# Valid values: true|false
hidecursor true

# This command is executed after a succesful login.
# you can place the %session and %theme variables
# to handle launching of specific commands in .xinitrc
# depending of chosen session and slim theme
#
# NOTE: if your system does not have bash you need
# to adjust the command according to your preferred shell,
# i.e. for freebsd use:
# login_cmd exec /bin/sh - ~/.xsession %session
login_cmd exec /bin/bash -login ~/.xinitrc %session

# Commands executed when starting and exiting a session.
# They can be used for registering a X11 session with
# sessreg. You can use the %user variable
#
# sessionstart_cmd some command
# sessionstop_cmd some command

# Start in daemon mode. Valid values: yes | no
# Note that this can overridden by the command line
# option"-d"
# daemon yes

# Available sessions (first one is the default).
# The current chosen session name is replaced in the login_cmd
# above, so your login command can handle different sessions.
# see the xinitrc.sample file shipped with slim sources
sessions icewm,fluxbox

# Executed when pressing F11 (requires imagemagick)
screenshot_cmd scrot /tmp/slim.png

# welcome message. Available variables: %host, %domain
welcome_msg (Press F1 to toggle sessions)

# shutdown / reboot messages
shutdown_msg The system is shutting down...
reboot_msg The system is rebooting...

# default user, leave blank or remove this line
# for avoid pre-loading the username.
default_user library

# current theme, use comma separated list to specify a set to
# randomly choose from
current_theme antiX

# Lock file
lockfile /var/run/slim.lock

# Log file
logfile /var/log/slim.log

I'm sorry, but I don't see where to add quotes or anything around the above slim.conf part.
TIA

I didn't realize you were using version 7. Later versions have an updates slim which has the option for auto login. You may just be able to update slim and let it over write slim.conf to get the option.

All users should be able to shutdown. Maybe we need to edit /etc/sudoers to allow it.

For starting an application i would use the start up file from that environment or .xinitrc just to make things simple.

Today a friend donated a 500 MHz PIII for this project, so I just finished installing version 8. I can see the auto login in slim.conf, so will work on that tomorrow. But right now I can't seem to find where I add users.

That option would be in the Mepis tools. If you run, as root, muser in a terminal it will start for you..