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LightDM GTK Greeter

LightDM GTK Greeter is a greeter that has moderate requirements (GTK).

This project is one of many greeters for LightDM.

About LightDM

LightDM is a cross-desktop display manager. A display manager is a daemon that:

  • Runs display servers (e.g. X) where necessary.
  • Runs greeters to allow users to pick which user account and session type to use.
  • Allows greeters to perform authentication using PAM.
  • Runs session processes once authentication is complete.
  • Provides remote graphical login options.

Key features of LightDM are:

  • Cross-desktop - supports different desktop technologies.
  • Supports different display technologies (X, Mir, Wayland ...).
  • Lightweight - low memory usage and fast performance.
  • Guest sessions.
  • Supports remote login (incoming - XDMCP, VNC, outgoing - XDMCP, pluggable).
  • Comprehensive test suite.


LightDM configuration is provided by the following files:


LightDM GTK Greeter uses lightdm-gtk-greeter.conf for its configuration.

System provided configuration should be stored in /usr/share/lightdm/lightdm.conf.d/. System administrators can override this configuration by adding files to /etc/lightdm/lightdm.conf.d/ and /etc/lightdm/lightdm.conf. Files are read in the above order and combined together to make the LightDM configuration.

For example, if a sysadmin wanted to override the system configured default session (provided in /usr/share/lightdm/lightdm.conf.d) they should make a file /etc/lightdm/lightdm.conf.d/50-myconfig.conf with the following:


Configuration is in keyfile format. For most installations you will want to change the keys in the [Seat:*] section as this applies to all seats on the system (normally just one). A configuration file showing all the possible keys is provided in data/lightdm.conf.


Questions about LightDM and LightDM GTK Greeter should be asked on the mailing list. All questions are welcome.

Stack Overflow and Ask Ubuntu are good sites for frequently asked questions.