Locale bus mechanism
systemd-localed.service is a system service that may be used as mechanism to change the system locale settings, as well as the console key mapping and default X11 key mapping. systemd-localed is automatically activated on request and terminates itself when it is unused.
The tool localectl(1) is a command line client to this service.
See org.freedesktop.locale1(5) and org.freedesktop.LogControl1(5) for a description of the D-Bus API.