Devuan GNU+Linux is a free software operating system for your
computer. Free software means you are free to use, copy
and distribute, study, change the software, and share your
modifications with the community.
software freedom, your way
apt install dbus-1-doc
doc : optional
simple interprocess messaging system (documentation)
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 API documentation for D-Bus, as well as
the protocol specification.
See the dbus description for more information about D-Bus in general.