Simple Desktop Display Manager

Simple Desktop Display Manager (SDDM) is a display manager (a graphical login program) for the X11 and Wayland windowing systems. SDDM was written from scratch in C++11 and supports theming via QML.

SDDM is free and open-source software subject to the terms of the GNU General Public License version 2 or later.

Adoption
In 2013, Fedora KDE members decided to default to SDDM in Fedora 21.

KDE chose SDDM to be the successor of the KDE Display Manager for KDE Plasma 5.

The LXQt developers recommend SDDM as a display manager.