The Light Display Manager (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 is available most distributions and is the recommended way to install. The package name is generally "lightdm".
The core LightDM project does not provide any greeter with it and you should install a greeter appropriate to your system. Popular greeter projects are:
- LightDM GTK+ Greeter - a greeter that has moderate requirements (GTK+).
- LightDM KDE - greeter used in KDE (Qt)
- LXqt Greeter - greeter used in LXqt (Qt)
- Pantheon Greeter - greeter used in Elementary OS (GTK+/Clutter).
- Unity Greeter - greeter used in Unity.
- Run with no greeter (automatic login only)
- Write your own...
LightDM configuration is provided by the following files:
/usr/share/lightdm/lightdm.conf.d/*.conf /etc/lightdm/lightdm.conf.d/*.conf /etc/lightdm/lightdm.conf
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 sysadmind 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.
See Common Configuration for common configuration options.
Questions should be asked on the mailing list. All questions are welcome.
Here are links to some distributions that package it: