Editing GDK (section)

===Windowing systems===
GDK contains back-ends to a couple of [[windowing system]]s, namely to the [[X11]] and [[Wayland (display server protocol)|Wayland]] protocols, to [[Quartz Compositor|Quartz]] and [[Graphics Device Interface|GDI]], 
and even to the [[Hypertext Transfer Protocol]] (HTTP) engine Broadway.{{cn|date=April 2023}}

With the release of GNOME 3.16 in March 2015, GDK obtained an experimental back-end for the [[Mir_(software)|Mir]] display server protocol.<ref>{{cite web |url=https://git.gnome.org/browse/gtk+/commit/?id=0f26b26f1d93f002ccd5fe6b6fd636172bfbb24b |title=add an experimental backend for mir}}</ref> The Mir display server protocol is a product by [[Canonical (company)|Canonical]] for their [[Ubuntu (operating system)|Ubuntu]] distribution of Linux, which they intend to compete with the Wayland display server protocol; so far, it is implemented only in Ubuntu.

At present, no back-end exists for [[Direct Rendering Manager#Kernel Mode Setting|KMS]].{{cn|date=April 2023}}

The environment variable ''GDK_BACKEND'' can be used to start an application and force this instance of it to use a certain windowing system:<br />
<code>GDK_BACKEND=wayland gnome-calculator</code><br />
<code>GDK_BACKEND=wayland CLUTTER_BACKEND=wayland cheese</code>