LXDM

LXDM is a lightweight display manager with UI implemented in GTK+.

Internet connectivity, unless the packages have been pre-fetched into a local cache.
A non-root user account.
The community repository must be enabled.
Set up eudev.
Install and configure D-Bus. without D-Bus icons and keyboard shortcuts may be missing.
Install appropriate Graphics driver drivers for your hardware. Without graphics drivers, errors are likely to occur.

Installation

Install X11 and set it up using the setup-xorg-base script.

# setup-xorg-base

To install lxdm, execute:

# apk add lxdm

The main configuration file is /etc/lxdm/lxdm.conf.