dbus-user-session

Description

simple interprocess messaging system (systemd --user integration)
D-Bus is a message bus, used for sending messages between applications.
Conceptually, it fits somewhere in between raw sockets and CORBA in
terms of complexity.

On systemd systems, this package opts in to the session model in which
a user's session starts the first time they log in, and does not end
until all their login sessions have ended. This model merges all
parallel non-graphical login sessions (text mode, ssh, cron, etc.), and up
to one graphical session, into a single "user-session" or "super-session"
within which all background D-Bus services are shared.

Multiple graphical sessions per user are not currently supported in this
mode; as a result, it is particularly suitable for gdm, which responds to
requests to open a parallel graphical session by switching to the existing
graphical session and unlocking it.

To retain dbus' traditional session semantics, in which login sessions
are artificially isolated from each other, remove this package and install
dbus-x11 instead.

See the dbus package description for more information about D-Bus in general.