<s>
The	O
X	B-Application
font	I-Application
server	I-Application
(	O
xfs	O
)	O
provides	O
a	O
standard	O
mechanism	O
for	O
an	O
X	B-Operating_System
server	I-Operating_System
to	O
communicate	O
with	O
a	O
font	O
renderer	O
,	O
frequently	O
one	O
running	O
on	O
a	O
remote	O
machine	O
.	O
</s>
<s>
It	O
usually	O
runs	O
on	O
TCP	B-Protocol
port	O
7100	O
.	O
</s>
<s>
Such	O
fonts	O
are	O
rendered	O
by	O
the	O
client	O
,	O
not	O
by	O
the	O
server	O
,	O
with	O
the	O
support	O
of	O
the	O
Xft2	B-Application
or	O
Cairo	B-Language
libraries	O
and	O
the	O
XRender	B-Device
extension	O
.	O
</s>
<s>
Server-side	O
fonts	O
can	O
now	O
be	O
configured	O
in	O
the	O
X	B-Operating_System
server	I-Operating_System
configuration	O
files	O
.	O
</s>
<s>
For	O
example	O
,	O
will	O
set	O
the	O
server-side	O
fonts	O
for	O
Xorg	B-Operating_System
.	O
</s>
<s>
One	O
of	O
the	O
original	O
motivations	O
behind	O
xfs	O
was	O
the	O
single-threaded	O
nature	O
of	O
the	O
X	B-Operating_System
server	I-Operating_System
—	O
a	O
user	O
’s	O
X	B-Operating_System
session	O
could	O
seem	O
to	O
"	O
freeze	O
up	O
"	O
while	O
the	O
X	B-Operating_System
server	I-Operating_System
took	O
a	O
moment	O
to	O
rasterize	O
a	O
font	O
.	O
</s>
<s>
This	O
problem	O
with	O
the	O
X	B-Operating_System
server	I-Operating_System
(	O
which	O
remains	O
single-threaded	O
in	O
all	O
popular	O
implementations	O
to	O
this	O
day	O
)	O
has	O
been	O
mitigated	O
on	O
two	O
fronts	O
:	O
machines	O
have	O
gotten	O
much	O
faster	O
,	O
and	O
client-side	O
font	O
rendering	O
(	O
particularly	O
via	O
the	O
Xft	B-Application
library	O
)	O
has	O
become	O
the	O
norm	O
in	O
contemporary	O
software	O
.	O
</s>
