xdm
Explanation:
The name of the simple graphical login manager that comes with a vanilla X11 installation is xdm. XDM is the traditional graphical login manager for the X Window System, independent of any window manager or environment the user might choose. When it is run at system startup, it displays a graphical login prompt rather than the text-based login prompt at the console1. XDM is part of the xorg-x11-apps package, which provides the basic applications for the X Window System2. XDM is also one of the topics covered by the LPI Linux Professional - Exam 102 Objectives - Topic 111: Graphical Desktops3. Reference:
xorg-x11-apps - Linux Man Pages (1) - SysTutorials
LPI Linux Professional - Exam 102 Objectives - Topic 111: Graphical Desktops GitHub - iwamatsu/slim: SLiM (Simple Login Manager) is a graphical login manager for X11 slim-fork download | SourceForge.net Using the XDM Graphical Login Manager | FreeBSD 6 Unleashed - Flylib Xorg - ArchWiki How to remotely log in with full graphical desktop over X11 - Unix & Linux Stack Exchange