Internal Program Version: D-Bus  1.14.6

D-Bus is a message bus system, a simple way for applications to talk to
one another. D-Bus supplies both a system daemon and a
per-user-login-session daemon. Also, the message bus is built on top of
a general one-to-one message passing framework, which can be used by
any two apps to communicate directly (without going through the message
bus daemon)

https://dbus.freedesktop.org