dbus-x11 1.14.4-1ubuntu1 (ppc64el binary) in ubuntu lunar

 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.
 .
 This package contains the dbus-launch utility, which automatically
 launches one D-Bus session bus per X11 display per user. If the
 dbus-user-session package is also installed, it takes precedence over
 this package.
 .
 See the dbus description for more information about D-Bus in general.