LightDM


LightDM is a free and open-source X display manager that aims to be lightweight, fast, extensible and multi-desktop. It can use various front-ends to draw User Interface, also called Greeters. It also supports Wayland.
LightDM is the default display manager for Edubuntu, Xubuntu and Mythbuntu since 11.10 release, for Lubuntu since 12.04 release, for Kubuntu beginning with 12.10 until 15.04 for Linux Mint and Antergos.

Features

Features include:
LightDM has a simpler code base than GDM and does not load any GNOME libraries to work, but at the cost of some features, that the user may or may not need.

front-ends