<s>
Layout	B-Library
managers	I-Library
are	O
software	O
components	O
used	O
in	O
widget	B-Library
toolkits	I-Library
which	O
have	O
the	O
ability	O
to	O
lay	O
out	O
graphical	O
control	O
elements	O
by	O
their	O
relative	O
positions	O
without	O
using	O
distance	O
units	O
.	O
</s>
<s>
It	O
is	O
often	O
more	O
natural	O
to	O
define	O
component	O
layouts	O
in	O
this	O
manner	O
than	O
to	O
define	O
their	O
position	O
in	O
pixels	B-Algorithm
or	O
common	O
distance	O
units	O
,	O
so	O
a	O
number	O
of	O
popular	O
widget	B-Library
toolkits	I-Library
include	O
this	O
ability	O
by	O
default	O
.	O
</s>
<s>
Widget	B-Library
toolkits	I-Library
that	O
provide	O
this	O
function	O
can	O
generally	O
be	O
classified	O
into	O
two	O
groups	O
:	O
</s>
<s>
This	O
is	O
the	O
case	O
in	O
XUL	B-Application
and	O
the	O
.NET	B-Application
Framework	I-Application
widget	B-Library
toolkit	I-Library
(	O
both	O
in	O
Windows	B-Application
Forms	I-Application
and	O
in	O
XAML	B-Device
)	O
.	O
</s>
<s>
Those	O
where	O
the	O
layout	O
behavior	O
is	O
coded	O
in	O
layout	B-Library
managers	I-Library
,	O
that	O
can	O
be	O
applied	O
to	O
any	O
graphic	O
container	O
.	O
</s>
<s>
This	O
is	O
the	O
case	O
in	O
the	O
Swing	B-Language
widget	B-Library
toolkit	I-Library
that	O
is	O
part	O
of	O
the	O
Java	B-Library
API	I-Library
.	O
</s>
<s>
In	O
XUL	B-Application
,	O
like	O
the	O
container	O
to	O
stack	O
components	O
on	O
top	O
of	O
each	O
other	O
.	O
</s>
<s>
The	O
layout	B-Library
manager	I-Library
arranges	O
components	O
in	O
a	O
directional	O
flow	O
,	O
much	O
like	O
lines	O
of	O
text	O
in	O
a	O
paragraph	O
.	O
</s>
<s>
Other	O
layout	B-Library
managers	I-Library
are	O
GridLayout	O
managers	O
which	O
arrange	O
the	O
components	O
in	O
grid	O
form	O
and	O
BorderLayout	B-Library
managers	O
which	O
also	O
arranges	O
the	O
component	O
in	O
five	O
parts	O
of	O
the	O
frame	O
,	O
thus	O
:	O
south	O
,	O
north	O
,	O
west	O
,	O
east	O
and	O
center	O
.	O
</s>
