<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" type="topic" id="tech-d-bus" xml:lang="oc">
<info>
  <link type="guide" xref="tech" group="d-bus"/>
  <desc>Inter-process communication bus to provide APIs to other processes</desc>
  <revision pkgversion="3.0" date="2011-04-05" status="candidate"/>
</info>

<title>D-Bus</title>

<p>D-Bus is a message bus for sending messages between
various applications, the desktop, and low-level components of the system.
D-Bus provides a simple API for sending messages to particular services
and for broadcasting messages to all interested services.  D-Bus enables
different types of applications to communicate and integrate with each
other and with the desktop, providing better interaction and a richer
experience for the user.  </p>

<p>D-Bus provides a session bus and a system bus.  The session bus is
used by applications in a single user session, allowing them to share
data and event notifications and to integrate into the user's desktop.
For example, movie players can send a D-Bus message to prevent the
screensaver from activating while the user is watching a movie.</p>

<p>The system bus is a single message bus which runs independently of
any user sessions.  It can communicate with applications in any session,
enabling those applications to interact with system components without
dealing with low-level system details.  The system bus is used to provide
important functionality that users expect to work on their systems.  For
example, the system bus is used to monitor when network interfaces go up
or down, when external drives get plugged in, and when laptop batteries
are low.</p>

<p>D-Bus is developed jointly on <link href="http://www.freedesktop.org/">freedesktop.org</link>, so you can
use it with different desktop environments and applications.  Because
D-Bus is a cross-desktop project, you use it to create portable and
versatile software that seamlessly integrates with the user's desktop,
regardless of which desktop it is.</p>

  <p>GNOME provides full support for D-Bus using the GDBus APIs in
  <link xref="tech-gio">GIO</link>.</p>

<list style="compact">
  <item><p><link href="https://developer.gnome.org/gio/stable/">GIO Reference Manual</link></p></item>
  <item><p><link href="http://dbus.freedesktop.org/doc/dbus-tutorial.html">D-Bus Tutorial</link></p></item>
  <item><p><link href="http://dbus.freedesktop.org/doc/dbus-specification.html">D-Bus Specification</link></p></item>
</list>

</page>
