What is CDM?
CDM is a minimalistic, yet full-featured replacement for login-managers like slim, kdm, gdm and qingy that provides a fast, dialog-based login system without the overhead of the X Window System or the instability of qingy. CDM supports multiple users/sessions and can start virtually any DE/WM.
How to get CDM?
A package is available from the AUR.
You can configure CDM by editing /etc/cdmrc. It is fully documented and should be relatively easy to figure out.
Before you can use CDM, you must copy the xinitrc and bash_profile supplied in /usr/share/cdm/skel to the home directory of each user (or merge the contents of said files).
Login to the console and select your prefered session (or console, if allowed) from the menu. It's that simple!
Additional users may be logged in by switching to tty1 (ctrl+alt+f1). If the user is already logged in, CDM will automatically activate their pre-existing session.