gdm
GNOME Display Manager
gdm provides the equivalent of a "login:" prompt for X displays- it
pops up a login window and starts an X session.
It provides all the functionality of xdm, including XDMCP support for
managing remote displays.
The greeting window is written using the GNOME libraries and hence
looks like a GNOME application- even to the extent of supporting
themes! By default, the greeter is run as an unprivileged user for
security.
