<s>
GTK	O
(	O
formerly	O
GTK+	O
)	O
is	O
a	O
free	B-License
and	I-License
open-source	I-License
cross-platform	B-Operating_System
widget	B-Library
toolkit	I-Library
for	O
creating	O
graphical	B-Application
user	I-Application
interfaces	I-Application
(	O
GUIs	B-Application
)	O
.	O
</s>
<s>
It	O
is	O
licensed	O
under	O
the	O
terms	O
of	O
the	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
,	O
allowing	O
both	O
free	B-Application
and	O
proprietary	B-Application
software	I-Application
to	O
use	O
it	O
.	O
</s>
<s>
It	O
is	O
one	O
of	O
the	O
most	O
popular	O
toolkits	O
for	O
the	O
Wayland	B-Language
and	O
X11	B-Operating_System
windowing	B-Application
systems	I-Application
.	O
</s>
<s>
GTK1	O
is	O
independently	O
maintained	O
by	O
the	O
CinePaint	B-Application
project	O
.	O
</s>
<s>
The	O
GTK	O
library	B-Library
contains	O
a	O
set	O
of	O
graphical	O
control	O
elements	O
(	O
widgets	O
)	O
;	O
version	O
3.22.16	O
contains	O
186	O
active	O
and	O
36	O
deprecated	O
widgets	O
.	O
</s>
<s>
GTK	O
is	O
an	O
object-oriented	B-Language
widget	B-Library
toolkit	I-Library
written	O
in	O
the	O
programming	B-Language
language	I-Language
C	I-Language
;	O
it	O
uses	O
GObject	B-Language
,	O
that	O
is	O
the	O
GLib	B-Language
object	I-Language
system	I-Language
,	O
for	O
the	O
object	O
orientation	O
.	O
</s>
<s>
While	O
GTK	O
is	O
mainly	O
for	O
windowing	B-Application
systems	I-Application
based	O
on	O
X11	B-Operating_System
and	O
Wayland	B-Language
,	O
it	O
works	O
on	O
other	O
platforms	O
,	O
including	O
Microsoft	B-Application
Windows	I-Application
(	O
interfaced	O
with	O
the	O
Windows	B-Library
API	I-Library
)	O
,	O
and	O
macOS	B-Application
(	O
interfaced	O
with	O
Quartz	B-Operating_System
)	O
.	O
</s>
<s>
There	O
is	O
also	O
an	O
HTML5	B-Application
back-end	O
named	O
Broadway	O
.	O
</s>
<s>
Starting	O
with	O
version	O
2.8	O
,	O
released	O
in	O
2005	O
,	O
GTK	O
began	O
the	O
transition	O
to	O
using	O
Cairo	B-Language
to	O
render	O
most	O
of	O
its	O
graphical	O
control	O
elements	O
widgets	O
.	O
</s>
<s>
Since	O
GTK	O
version	O
3.0	O
,	O
all	O
rendering	O
is	O
done	O
using	O
Cairo	B-Language
.	O
</s>
<s>
GDK	B-Language
acts	O
as	O
a	O
wrapper	O
around	O
the	O
low-level	O
functions	O
provided	O
by	O
the	O
underlying	O
windowing	O
and	O
graphics	O
systems	O
.	O
</s>
<s>
GSK	O
is	O
the	O
rendering	O
and	O
scene	O
graph	O
API	B-Application
for	O
GTK	O
.	O
</s>
<s>
There	O
are	O
several	O
GUI	B-Application
designers	O
for	O
GTK	O
.	O
</s>
<s>
Glade	B-Language
,	O
supports	O
GtkBuilder	B-Language
,	O
which	O
is	O
a	O
GTK	O
built-in	O
GUI	B-Application
description	O
format	O
.	O
</s>
<s>
Crow	O
Designer	O
,	O
relies	O
on	O
its	O
own	O
GuiXml	O
format	O
and	O
GuiLoader	O
library	B-Library
.	O
</s>
<s>
Stetic	O
,	O
part	O
of	O
MonoDevelop	B-Language
,	O
oriented	O
toward	O
Gtk#	O
.	O
</s>
<s>
GtkBuilder	B-Language
allows	O
user	O
interfaces	O
to	O
be	O
designed	O
without	O
writing	O
code	O
.	O
</s>
<s>
The	O
interface	O
is	O
described	O
in	O
an	O
Extensible	B-Protocol
Markup	I-Protocol
Language	I-Protocol
(	O
XML	B-Protocol
)	O
file	O
,	O
which	O
is	O
then	O
loaded	O
at	O
runtime	O
and	O
the	O
objects	O
created	O
automatically	O
.	O
</s>
<s>
The	O
Glade	B-Language
Interface	I-Language
Designer	I-Language
allows	O
creation	O
of	O
the	O
user	O
interface	O
in	O
a	O
what	B-Application
you	I-Application
see	I-Application
is	I-Application
what	I-Application
you	I-Application
get	I-Application
(	O
WYSIWYG	B-Application
)	O
manner	O
.	O
</s>
<s>
Language	B-Application
bindings	I-Application
are	B-Language
available	I-Language
for	O
using	O
GTK	O
from	O
languages	O
other	O
than	O
C	B-Language
,	O
including	O
C++	B-Language
,	O
Genie	B-Language
,	O
JavaScript	B-Language
,	O
Perl	B-Language
,	O
Python	B-Language
,	O
Vala	B-Language
,	O
and	O
others	B-Language
.	O
</s>
<s>
Gtk#	O
is	O
a	O
set	O
of	O
.NET	B-Application
Framework	I-Application
bindings	O
for	O
the	O
GTK	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
toolkit	B-Library
and	O
assorted	O
GNOME	B-Application
libraries	B-Library
.	O
</s>
<s>
The	O
library	B-Library
facilitates	O
building	O
graphical	O
GNOME	B-Application
applications	O
using	O
Mono	B-Application
or	O
any	O
other	O
compliant	O
Common	O
Language	O
Runtime	O
(	O
CLR	O
)	O
.	O
</s>
<s>
Gtk#	O
is	O
an	O
event-driven	O
system	O
like	O
any	O
other	O
modern	O
windowing	O
library	B-Library
where	O
every	O
widget	O
allows	O
associating	O
handler	O
methods	O
,	O
which	O
get	O
called	O
when	O
certain	O
events	O
occur	O
.	O
</s>
<s>
Applications	O
built	O
using	O
Gtk#	O
will	O
run	O
on	O
many	O
platforms	O
including	O
Linux	B-Application
,	O
Windows	O
and	O
macOS	B-Application
.	O
</s>
<s>
The	O
Mono	B-Application
packages	O
for	O
Windows	O
include	O
GTK	O
,	O
Gtk#	O
and	O
a	O
native	O
theme	B-Application
to	O
make	O
applications	O
look	O
like	O
native	O
Windows	B-Application
applications	I-Application
.	O
</s>
<s>
Starting	O
with	O
Mono	B-Application
1.9	O
,	O
running	O
Gtk#	O
applications	O
on	O
macOS	B-Application
no	O
longer	O
requires	O
running	O
an	O
X11	B-Operating_System
server	I-Operating_System
.	O
</s>
<s>
Glade	B-Language
Interface	I-Language
Designer	I-Language
can	O
be	O
used	O
with	O
the	O
Glade#	O
bindings	O
to	O
easily	O
design	O
GUI	B-Application
applications	O
.	O
</s>
<s>
A	O
GUI	B-Application
designer	O
named	O
Stetic	O
is	O
integrated	O
with	O
the	O
MonoDevelop	B-Language
integrated	B-Application
development	I-Application
environment	I-Application
(	O
IDE	O
)	O
.	O
</s>
<s>
In	O
addition	O
to	O
support	O
the	O
standard	O
GTK/GNOME	O
stack	O
of	O
development	O
tools	O
,	O
the	O
assembly	O
provides	O
a	O
bridge	O
to	O
consume	O
functionality	O
available	O
on	O
the	O
.NET	B-Application
stack	O
.	O
</s>
<s>
,	O
Gtk#	O
support	O
for	O
Gtk3	O
remains	O
in	O
the	O
preview	O
phase	O
and	O
forked	O
projects	O
,	O
such	O
as	O
GtkSharp	O
,	O
have	O
been	O
founded	O
to	O
provide	O
full	O
Gtk3	O
support	O
for	O
C#	B-Application
and	O
other	O
CLI	O
languages	O
.	O
</s>
<s>
The	O
lack	O
of	O
a	O
released	O
version	O
of	O
Gtk#	O
with	O
support	O
for	O
Gtk3	O
was	O
cited	O
as	O
a	O
reason	O
to	O
remove	O
the	O
Banshee	B-Language
media	I-Language
player	I-Language
in	O
Ubuntu	B-Operating_System
12.04	O
.	O
</s>
<s>
GTK	O
is	O
mainly	O
developed	O
by	O
The	O
GNOME	B-Application
Project	O
,	O
which	O
also	O
develops	O
the	O
GNOME	B-Application
Development	O
Platform	O
and	O
the	O
GNOME	B-Application
Desktop	I-Application
Environment	I-Application
.	O
</s>
<s>
GNOME	B-Application
developers	O
and	O
users	O
gather	O
at	O
an	O
annual	O
GNOME	B-Application
Users	I-Application
And	I-Application
Developers	I-Application
European	I-Application
Conference	I-Application
GUADEC	B-Application
meeting	O
to	O
discuss	O
GNOME	B-Application
's	O
current	O
state	O
and	O
future	O
direction	O
.	O
</s>
<s>
GNOME	B-Application
incorporates	O
standards	O
and	O
programs	O
from	O
freedesktop.org	B-Application
to	O
better	O
interoperate	O
with	O
other	O
desktops	O
.	O
</s>
<s>
GTK	O
is	O
mainly	O
written	O
in	O
C	B-Language
.	O
Many	O
language	B-Application
bindings	I-Application
are	B-Language
available	I-Language
.	O
</s>
<s>
GTK	O
version	O
3.22	O
,	O
released	O
in	O
Autumn	O
2016	O
,	O
was	O
planned	O
to	O
be	O
the	O
last	O
3.x	O
release	O
,	O
although	O
version	O
3.24	O
followed	O
in	O
Fall	O
2018	O
with	O
the	O
delay	O
of	O
GTK	O
4	O
.	O
</s>
<s>
For	O
example	O
,	O
as	O
of	O
January	O
2022	O
,	O
GIMP	B-Application
is	O
still	O
being	O
ported	O
to	O
GTK	O
3	O
.	O
</s>
<s>
GTK	O
(	O
and	O
GNOME	B-Application
,	O
GLib	B-Language
,	O
etc	O
.	O
)	O
</s>
<s>
formerly	O
utilized	O
the	O
GNU	B-Application
Build	I-Application
System	I-Application
(	O
named	O
Autotools	B-Application
)	O
as	O
the	O
build	B-Application
automation	I-Application
system	O
of	O
choice	O
.	O
</s>
<s>
Since	O
14	O
Aug	O
2017	O
,	O
the	O
master	O
branch	O
of	O
GTK	O
has	O
been	O
built	O
with	O
Meson	B-Application
,	O
and	O
the	O
Autotools	B-Application
build	B-Application
system	I-Application
files	O
have	O
been	O
dropped	O
.	O
</s>
<s>
The	O
most	O
common	O
criticism	O
of	O
GTK	O
is	O
the	O
lack	O
of	O
backward-compatibility	O
in	O
major	O
updates	O
,	O
most	O
notably	O
in	O
the	O
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
and	O
theming	O
.	O
</s>
<s>
The	O
compatibility	O
breaks	O
between	O
minor	O
releases	O
during	O
the	O
GTK	O
3.x	O
development	O
cycle	O
was	O
explained	O
by	O
Benjamin	O
Otte	O
as	O
due	O
to	O
strong	O
pressures	O
to	O
innovate	O
,	O
such	O
as	O
providing	O
the	O
features	O
modern	O
users	O
expect	O
and	O
supporting	O
the	O
increasingly	O
influential	O
Wayland	B-Language
display	I-Language
server	I-Language
protocol	I-Language
.	O
</s>
<s>
Similarly	O
,	O
recent	O
changes	O
to	O
theming	O
are	O
specifically	O
intended	O
to	O
improve	O
and	O
stabilise	O
that	O
part	O
of	O
the	O
API	B-Application
,	O
meaning	O
some	O
investment	O
now	O
should	O
be	O
rewarded	O
later	O
.	O
</s>
<s>
Hong	O
Jen	O
Yee	O
,	O
developer	O
of	O
LXDE	B-Language
(	O
the	O
GTK	O
version	O
of	O
which	O
was	O
dropped	O
and	O
all	O
efforts	O
focused	O
on	O
the	O
Qt	B-Language
port	I-Language
)	O
,	O
expressed	O
disdain	O
for	O
version	O
3	O
of	O
the	O
GTK	O
toolkit	B-Library
's	O
radical	O
API	B-Application
changes	O
and	O
increased	O
memory	O
usage	O
,	O
and	O
ported	O
PCMan	B-Language
File	I-Language
Manager	I-Language
(	O
PCManFM	B-Language
)	O
to	O
Qt	B-Language
.	O
</s>
<s>
PCManFM	B-Language
is	O
being	O
developed	O
with	O
a	O
GTK	O
and	O
with	O
a	O
Qt	B-Language
backend	O
at	O
the	O
same	O
time	O
.	O
</s>
<s>
The	O
Audacious	B-Language
music	O
player	O
moved	O
to	O
Qt	B-Language
in	O
version	O
3.6	O
.	O
</s>
<s>
The	O
reasons	O
stated	O
by	O
the	O
developers	O
for	O
this	O
include	O
a	O
transition	O
to	O
client-side	O
window	O
decorations	O
,	O
which	O
they	O
claim	O
cause	O
the	O
application	O
to	O
look	O
"	O
GNOME-y	O
and	O
out	O
of	O
place.	O
"	O
</s>
<s>
Wireshark	B-Language
has	O
switched	O
to	O
Qt	B-Language
due	O
to	O
not	O
having	O
a	O
good	O
experience	O
with	O
GTK	O
's	O
cross-platform	B-Operating_System
support	O
.	O
</s>
<s>
Some	O
notable	O
applications	O
that	O
use	O
GTK	O
as	O
a	O
widget	B-Library
toolkit	I-Library
include	O
:	O
</s>
<s>
Several	O
desktop	O
environments	O
utilize	O
GTK	O
as	O
the	O
widget	B-Library
toolkit	I-Library
.	O
</s>
<s>
GTK	O
programs	O
can	O
be	O
run	O
on	O
desktop	O
environments	O
based	O
on	O
X11	B-Operating_System
and	O
Wayland	B-Language
,	O
or	O
window	B-Application
managers	I-Application
even	O
those	O
not	O
made	O
with	O
GTK	O
,	O
provided	O
the	O
needed	O
libraries	B-Library
are	O
installed	O
;	O
this	O
includes	O
macOS	B-Application
if	O
X11.app	B-Operating_System
is	O
installed	O
.	O
</s>
<s>
GTK	O
can	O
be	O
also	O
run	O
on	O
Microsoft	B-Application
Windows	I-Application
,	O
where	O
it	O
is	O
used	O
by	O
some	O
popular	O
cross-platform	B-Operating_System
applications	O
like	O
Pidgin	B-Protocol
and	O
GIMP	B-Application
.	O
</s>
<s>
wxWidgets	B-Language
,	O
a	O
cross-platform	B-Operating_System
GUI	B-Application
tool-kit	O
,	O
uses	O
GTK	O
on	O
Linux	B-Application
by	O
default	O
.	O
</s>
<s>
Other	O
ports	O
include	O
DirectFB	B-Application
(	O
used	O
by	O
the	O
Debian	B-Language
installer	I-Language
,	O
for	O
example	O
)	O
and	O
ncurses	B-Language
.	O
</s>
<s>
The	O
following	O
window	B-Application
managers	I-Application
use	O
GTK	O
:	O
</s>
<s>
GtkSourceView	O
is	O
maintained	O
by	O
GNOME	B-Application
separately	O
from	O
GTK	O
as	O
a	O
library	B-Library
:	O
gtksourceview	O
.	O
</s>
<s>
GtkSpell	O
is	O
a	O
library	B-Library
separate	O
from	O
GTK	O
.	O
</s>
<s>
GtkSpell	O
depends	O
on	O
GTK	O
and	O
Enchant	B-Application
.	O
</s>
<s>
Enchant	B-Application
is	O
a	O
wrapper	O
for	O
ispell	O
,	O
hunspell	B-Application
,	O
etc.	O
,	O
the	O
actual	O
spell	B-Application
checker	I-Application
engine/software	O
.	O
</s>
<s>
GTK	O
was	O
originally	O
designed	O
and	O
used	O
in	O
the	O
GNU	B-Application
Image	I-Application
Manipulation	I-Application
Program	I-Application
(	O
GIMP	B-Application
)	O
as	O
a	O
replacement	O
of	O
the	O
Motif	B-Application
toolkit	I-Application
;	O
at	O
some	O
point	O
Peter	O
Mattis	O
became	O
disenchanted	O
with	O
Motif	B-Application
and	O
began	O
to	O
write	O
his	O
own	O
GUI	B-Library
toolkit	I-Library
named	O
the	B-Application
GIMP	I-Application
toolkit	B-Library
and	O
had	O
successfully	O
replaced	O
Motif	B-Application
by	O
the	O
0.60	O
release	O
of	O
GIMP	B-Application
.	O
</s>
<s>
Finally	O
GTK	O
was	O
re-written	O
to	O
be	O
object-oriented	B-Language
and	O
was	O
renamed	O
GTK+	O
.	O
</s>
<s>
This	O
was	O
first	O
used	O
in	O
the	O
0.99	O
release	O
of	O
GIMP	B-Application
.	O
</s>
<s>
GTK	O
was	O
subsequently	O
adopted	O
for	O
maintenance	O
by	O
the	O
GNOME	B-Language
Foundation	I-Language
,	O
which	O
uses	O
it	O
in	O
the	O
GNOME	B-Application
desktop	I-Application
environment	I-Application
.	O
</s>
<s>
The	O
GTK	O
2.0.0	O
release	O
series	O
introduced	O
new	O
features	O
which	O
include	O
improved	O
text	O
rendering	O
using	O
Pango	B-Language
,	O
a	O
new	O
theme	B-Application
engine	O
,	O
improved	O
accessibility	O
using	O
the	O
Accessibility	B-Language
Toolkit	I-Language
,	O
transition	O
to	O
Unicode	O
using	O
UTF-8	O
strings	O
,	O
and	O
a	O
more	O
flexible	O
API	B-Application
.	O
</s>
<s>
Starting	O
with	O
version	O
2.8	O
,	O
GTK	O
2	O
depends	O
on	O
the	O
Cairo	B-Language
graphics	I-Language
library	I-Language
for	O
rendering	O
vector	O
graphics	O
.	O
</s>
<s>
GTK	O
version	O
3.0.0	O
included	O
revised	O
input	O
device	O
handling	O
,	O
support	O
for	O
themes	O
written	O
with	O
CSS-like	O
syntax	O
,	O
and	O
the	O
ability	O
to	O
receive	O
information	O
about	O
other	O
opened	O
GTK	O
applications	O
.	O
</s>
<s>
With	O
Quartz-backend	O
GTK	O
is	O
available	O
in	O
macOS	B-Application
.	O
</s>
<s>
After	O
GTK	O
2.24.10	O
and	O
3.6.4	O
Development	O
of	O
Windows	O
with	O
Installer	O
was	O
closed	O
by	O
Gnome	B-Application
.	O
</s>
<s>
A	O
version	O
for	O
Windows	O
64-bit	O
is	O
prepared	O
by	O
Tom	O
Schoonjans	O
with	O
2.24.33	O
(	O
actual	O
like	O
Linux	B-Application
)	O
and	O
3.24.24	O
(	O
actual	O
like	O
Linux	B-Application
)	O
from	O
January	O
2021	O
available	O
.	O
</s>
<s>
Windows	O
10	O
's	O
Fall	O
Creators	O
Update	O
includes	O
Windows	O
Subsystem	O
for	O
Linux	B-Application
(	O
WSL	O
)	O
.	O
</s>
<s>
With	O
Linux	B-Application
distributions	O
like	O
Ubuntu	B-Operating_System
or	O
Debian	O
available	O
from	O
the	B-Application
Microsoft	I-Application
Store	I-Application
and	O
an	O
X	B-Operating_System
server	O
like	O
Xming	O
or	O
VcXsvr	O
,	O
thousands	O
of	O
programs	O
like	O
GTK	O
2	O
or	O
3	O
can	O
run	O
with	O
X	B-Operating_System
or	O
terminal	O
support	O
.	O
</s>
<s>
HP	O
stated	O
that	O
their	O
goal	O
was	O
to	O
merge	O
the	O
needed	O
OpenVMS	B-Operating_System
changes	O
into	O
the	O
GTK	O
Version	O
1.3	O
development	O
stream	O
,	O
however	O
this	O
never	O
materialised	O
.	O
</s>
<s>
The	O
latest	O
version	O
of	O
GTK	O
for	O
OpenVMS	B-Operating_System
is	O
version	O
1.2.10	O
.	O
</s>
<s>
The	O
last	O
to	O
support	O
Windows	O
98/Me	O
2.6.10	O
2005-08-13	O
Most	O
widgets	O
are	O
rendered	O
by	O
Cairo	B-Language
2.8.20	O
2006-07-03	O
New	O
widgets	O
:	O
</s>
<s>
To	O
remove	O
much	O
of	O
the	O
necessary	O
IPC	O
between	O
the	O
X11	B-Operating_System
application	O
and	O
the	O
X11	B-Operating_System
server	I-Operating_System
,	O
GDK	B-Language
is	O
rewritten	O
(	O
mainly	O
by	O
Alexander	O
Larsson	O
)	O
to	O
use	O
"	O
client-side	O
windows	O
"	O
,	O
i.e.	O
,	O
the	O
GdkWindow	O
,	O
which	O
every	O
widget	O
must	O
have	O
,	O
belongs	O
now	O
to	O
the	O
client	O
2.18.9	O
2010-03-23	O
New	O
widgets	O
:	O
</s>
<s>
XInput2	O
,	O
theme	B-Application
API	B-Application
is	O
based	O
on	O
Cascading	B-Language
Style	I-Language
Sheets	I-Language
(	O
CSS	B-Language
)	O
,	O
worsening	O
the	O
achievable	O
performance	O
for	O
60	O
Hz	O
frame	O
rates	O
3.0.12	O
2011-09-25	O
New	O
widgets	O
:	O
</s>
<s>
More	O
complete	O
CSS	B-Language
theming	O
support	O
3.4.4	O
2012-09-24	O
New	O
widgets	O
:	O
</s>
<s>
Deprecate	O
a	O
few	O
APIs	B-Application
that	O
are	O
gone	O
in	O
GTK	O
4	O
:	O
</s>
<s>
3.90	O
2017-10-18	O
As	O
GNOME	B-Application
3.26	O
was	O
released	O
already	O
on	O
September	O
13	O
,	O
2017	O
,	O
it	O
was	O
not	O
based	O
on	O
GTK	O
3.92	O
.	O
</s>
<s>
GNU	B-Application
autotools	I-Application
was	O
replaced	O
with	O
Meson	B-Application
.	O
</s>
<s>
GtkMediaControls	O
3.933.94.0	O
2019-05-07	O
The	O
command	O
has	O
gained	O
a	O
option	O
to	O
convert	O
GTK3	O
ui	O
files	O
to	O
GTK4	O
;	O
though	O
with	O
AMTK	O
menus	O
,	O
toolbars	O
or	O
other	O
objects	O
like	O
GtkShortcutsWindow	O
are	O
created	O
programmatically	O
(	O
not	O
with	O
a	O
*	O
.ui	O
file	O
)	O
,	O
but	O
with	O
convenient	O
APIs	B-Application
.	O
</s>
<s>
A	O
new	O
layout	O
manager3.98.5	O
2020-07-31	O
Introduced	O
successor	O
to	O
Accessibility	B-Language
Toolkit	I-Language
(	O
ATK	B-Language
)	O
.	O
</s>
