There are 2 repositories under display-manager topic.
A Minimal, Configurable, Single-User GTK3 LightDM Greeter
DisplayMagician is an open source tool for automatically configuring your displays and sound for a game or application from a single Windows Shortcut.
An open source display profile management program for Windows with support for NVIDIA Surround
Template-oriented driver for e-paper displays
A Beautiful Collection Of SLiM Themes.
An open-source Python library which can modify your Mac's display settings manually or automatically.
A Mac app and command-line tool for fiddling with display mirroring: on/off/toggle
A sddm theme inspired by Serial experiments lain.
WindowsDisplayAPI is a .Net wrapper for Windows Display and Windows CCD APIs
minimal(istic) lightdm-webkit2-greeter theme
Saluto — A WebKit LightDM Theme
Lightweight Wayland compositor for embedded devices
Display manager/Login Screen for dahliaOS
Universal Display Driver for Raspberry Pi
Puts your monitors to sleep at the click of a button
TUI (ncurses-like) display manager
PAM management system to control access to host
A lightweight digital signage management solution.
MacOSX command line program for retrieving and updating display related settings
Smart Thermostat control from smartphone
A macOS command line tool to manage an arrangement and configuration of your displays.