<s>
Tk	B-Application
is	O
a	O
free	B-License
and	I-License
open-source	I-License
,	O
cross-platform	B-Operating_System
widget	B-Library
toolkit	I-Library
that	O
provides	O
a	O
library	O
of	O
basic	O
elements	O
of	O
GUI	B-Application
widgets	O
for	O
building	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
in	O
many	O
programming	O
languages	O
.	O
</s>
<s>
Tk	B-Application
provides	O
a	O
number	O
of	O
widgets	O
commonly	O
needed	O
to	O
develop	O
desktop	O
applications	O
,	O
such	O
as	O
button	O
,	O
menu	O
,	O
canvas	O
,	O
text	O
,	O
frame	O
,	O
label	O
,	O
etc	O
.	O
</s>
<s>
Tk	B-Application
has	O
been	O
ported	O
to	O
run	O
on	O
most	O
flavors	O
of	O
Linux	B-Application
,	O
Mac	B-Application
OS	I-Application
,	O
Unix	B-Application
,	O
and	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Like	O
Tcl	B-Operating_System
,	O
Tk	B-Application
supports	O
Unicode	O
within	O
the	O
Basic	O
Multilingual	O
Plane	O
,	O
but	O
it	O
has	O
not	O
yet	O
been	O
extended	O
to	O
handle	O
the	O
current	O
extended	O
full	O
Unicode	O
(	O
e.g.	O
,	O
UTF-16	O
from	O
UCS-2	O
that	O
Tk	B-Application
supports	O
)	O
.	O
</s>
<s>
Tk	B-Application
was	O
designed	O
to	O
be	O
extended	O
,	O
and	O
a	O
wide	O
range	O
of	O
extensions	O
are	O
available	O
that	O
offer	O
new	O
widgets	O
or	O
other	O
capabilities	O
.	O
</s>
<s>
Since	O
Tcl/Tk	B-Operating_System
8	O
,	O
it	O
offers	O
"	O
native	O
look	O
and	O
feel	O
"	O
(	O
for	O
instance	O
,	O
menus	O
and	O
buttons	O
are	O
displayed	O
in	O
the	O
manner	O
of	O
"	O
native	O
"	O
software	O
for	O
any	O
given	O
platform	O
)	O
.	O
</s>
<s>
Highlights	O
of	O
version	O
8.5	O
include	O
a	O
new	O
theming	O
engine	O
,	O
originally	O
called	O
Tk	B-Application
Tile	O
,	O
but	O
it	O
is	O
now	O
generally	O
referred	O
to	O
as	O
"	O
themed	O
Tk	B-Application
"	O
,	O
as	O
well	O
as	O
improved	O
font	O
rendering	O
.	O
</s>
<s>
Tk	B-Application
was	O
developed	O
by	O
John	O
Ousterhout	O
as	O
an	O
extension	O
for	O
the	O
Tcl	B-Operating_System
scripting	O
language	O
.	O
</s>
<s>
Tk	B-Application
versioning	O
was	O
done	O
separately	O
from	O
Tcl	B-Operating_System
until	O
version	O
8.0	O
.	O
</s>
<s>
Tk	B-Application
was	O
written	O
originally	O
for	O
Unix/X11	O
,	O
and	O
proved	O
extremely	O
popular	O
with	O
programmers	O
in	O
the	O
1990s	O
by	O
virtue	O
of	O
its	O
being	O
easier	O
to	O
learn	O
and	O
use	O
than	O
Motif	B-Application
and	O
other	O
X11	O
toolkits	O
of	O
the	O
time	O
.	O
</s>
<s>
Tk	B-Application
was	O
also	O
ported	O
to	O
Microsoft	B-Application
Windows	I-Application
and	O
Macintosh	O
platforms	O
,	O
starting	O
with	O
Tk	B-Application
4.2	O
and	O
improved	O
with	O
native	O
look	O
and	O
feel	O
in	O
Tk	B-Application
8.0	O
(	O
released	O
1997	O
)	O
.	O
</s>
<s>
To	O
mark	O
the	O
popularity	O
and	O
significance	O
of	O
Tk	B-Application
in	O
the	O
1990s	O
,	O
Ousterhout	O
was	O
given	O
the	O
ACM	O
Software	O
System	O
Award	O
in	O
1997	O
for	O
Tcl/Tk	B-Operating_System
:	O
</s>
<s>
Interest	O
in	O
Tk	B-Application
waned	O
significantly	O
from	O
the	O
late	O
1990s	O
and	O
onward	O
.	O
</s>
<s>
The	O
default	O
look	O
and	O
feel	O
on	O
Unix	B-Application
still	O
emulated	O
Motif	B-Application
,	O
despite	O
the	O
mainstream	O
replacement	O
of	O
Motif	B-Application
by	O
toolkits	O
such	O
as	O
FLTK	B-Language
,	O
Qt	B-Language
and	O
GTK	B-Application
.	O
</s>
<s>
trees	O
,	O
combo	O
boxes	O
,	O
tabbed	O
notebooks	O
)	O
were	O
not	O
available	O
in	O
the	O
Tk	B-Application
core	O
,	O
but	O
only	O
via	O
multiple	O
,	O
often	O
competing	O
add-ons	O
.	O
</s>
<s>
Tk	B-Application
8.5	O
,	O
released	O
in	O
late	O
2007	O
,	O
corrected	O
some	O
of	O
these	O
problems	O
by	O
adding	O
missing	O
widgets	O
to	O
the	O
core	O
,	O
introducing	O
a	O
new	O
theming	O
engine	O
and	O
modernizing	O
the	O
look	O
and	O
feel	O
on	O
Unix	B-Application
.	O
</s>
<s>
However	O
,	O
because	O
some	O
code	O
changes	O
were	O
required	O
to	O
incorporate	O
these	O
advancements	O
,	O
many	O
existing	O
applications	O
retain	O
the	O
older	O
Motif-inspired	O
feel	O
that	O
Tk	B-Application
had	O
become	O
known	O
for	O
.	O
</s>
<s>
Tk	B-Application
is	O
a	O
platform-independent	B-Operating_System
GUI	B-Library
framework	I-Library
developed	O
for	O
Tcl	B-Operating_System
.	O
</s>
<s>
From	O
a	O
Tcl	B-Operating_System
shell	O
(	O
tclsh	O
)	O
,	O
Tk	B-Application
may	O
be	O
invoked	O
using	O
the	O
command	O
package	O
require	O
Tk	B-Application
.	O
</s>
<s>
The	O
program	O
wish	B-Language
(	O
WIndowing	O
SHell	O
)	O
provides	O
a	O
way	O
to	O
run	O
a	O
tclsh	O
shell	O
in	O
a	O
graphical	O
window	O
as	O
well	O
as	O
providing	O
Tk	B-Application
.	O
</s>
<s>
Tk	B-Application
has	O
the	O
following	O
characteristics	O
:	O
</s>
<s>
Platform-independent	B-Operating_System
:	O
Like	O
Tcl	B-Operating_System
,	O
Tk	B-Application
is	O
interpreted	O
.	O
</s>
<s>
It	O
has	O
been	O
ported	O
to	O
multiple	B-Operating_System
platforms	I-Operating_System
and	O
can	O
easily	O
run	O
on	O
all	O
of	O
them	O
without	O
modification	O
.	O
</s>
<s>
Customizable	O
:	O
Almost	O
all	O
the	O
features	O
of	O
a	O
widget	O
in	O
Tk	B-Application
are	O
customizable	O
through	O
options	O
during	O
the	O
creation	O
of	O
the	O
widget	O
or	O
later	O
on	O
through	O
the	O
configure	O
command	O
.	O
</s>
<s>
A	O
library	O
written	O
in	O
one	O
programming	O
language	O
may	O
be	O
used	O
in	O
another	O
language	O
if	O
bindings	B-Application
are	O
written	O
;	O
Tk	B-Application
is	O
integrated	O
with	O
the	O
Tcl	B-Operating_System
language	O
.	O
</s>
<s>
Various	O
other	O
languages	O
have	O
bindings	B-Application
for	O
Tk	B-Application
,	O
a	O
partial	O
list	O
of	O
which	O
is	O
on	O
the	O
Tk	B-Application
website	O
.	O
</s>
<s>
Bindings	B-Application
exist	O
for	O
additional	O
languages	O
which	O
might	O
not	O
be	O
listed	O
,	O
including	O
Ada	B-Language
(	O
called	O
TASH	O
)	O
,	O
Haskell	B-Language
(	O
called	O
HTk	O
)	O
,	O
Perl	B-Language
,	O
Python	B-Language
(	O
called	O
Tkinter	B-Language
)	O
,	O
R	B-Language
(	O
through	O
the	O
standard	O
package	O
:	O
tcltk	B-Operating_System
)	O
,	O
Ruby	B-Language
,	O
Rexx	B-Language
,	O
and	O
Common	B-Language
Lisp	I-Language
.	O
</s>
<s>
There	O
are	O
several	O
ways	O
to	O
use	O
Tk	B-Application
from	O
Perl	B-Language
:	O
the	O
Tcl::Tk	O
and	O
Tkx	O
Perl	B-Language
modules	O
,	O
both	O
of	O
which	O
use	O
Tcl	B-Operating_System
as	O
a	O
bridge	O
to	O
access	O
Tk	B-Application
,	O
and	O
Perl/Tk	O
,	O
which	O
provides	O
native	O
Perl	B-Language
access	O
to	O
Tk	B-Application
structures	O
.	O
</s>
<s>
The	O
Python	B-Language
binding	O
uses	O
Tcl	B-Operating_System
as	O
a	O
bridge	O
to	O
Tk	B-Application
.	O
</s>
<s>
Tk	B-Application
provides	O
various	O
widgets	O
.	O
</s>
