<s>
CDfs	B-Application
is	O
a	O
virtual	O
file	B-Application
system	I-Application
for	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
;	O
it	O
provides	O
access	O
to	O
data	O
and	O
audio	O
tracks	O
on	O
Compact	O
Discs	O
.	O
</s>
<s>
When	O
the	O
CDfs	B-Application
driver	B-Application
mounts	B-Application
a	O
Compact	O
Disc	O
,	O
it	O
represents	O
each	O
track	O
as	O
a	O
file	B-Operating_System
.	O
</s>
<s>
This	O
is	O
consistent	O
with	O
the	O
Unix	B-Application
convention	O
"	O
everything	B-Application
is	I-Application
a	I-Application
file	I-Application
"	O
.	O
</s>
<s>
CDfs	B-Application
supports	O
the	O
following	O
track	O
types	O
:	O
</s>
<s>
Red	O
Book	O
Compact	O
Disc	O
Digital	O
Audio	O
(	O
CD-DA	O
)	O
:	O
Appears	O
as	O
a	O
WAV	O
file	B-Operating_System
;	O
reading	O
from	O
it	O
initiates	O
DAE	O
ripping	O
.	O
</s>
<s>
White	O
Book	O
Video	O
CD	O
or	O
Super	O
Video	O
CD	O
video	O
:	O
Appears	O
as	O
a	O
playable	O
MPEG-1	B-Algorithm
file	B-Operating_System
containing	O
audio	O
and	O
video	O
streams	O
.	O
</s>
<s>
Yellow	B-Device
Book	I-Device
CD-ROM	B-Device
data	O
:	O
</s>
<s>
Hierarchical	B-Application
File	I-Application
System	I-Application
:	O
Appears	O
as	O
a	O
mountable	O
HFS	B-Application
file	B-Application
system	I-Application
disk	B-Application
image	I-Application
(	O
sans	O
partition	B-Application
table	O
)	O
.	O
</s>
<s>
ISO	B-Application
9660	I-Application
:	O
Each	O
session	O
appears	O
as	O
a	O
mountable	O
ISO	B-General_Concept
image	I-General_Concept
file	B-Operating_System
.	O
</s>
<s>
El	B-Device
Torito	I-Device
boot	O
file	B-Operating_System
:	O
Appears	O
as	O
a	O
single	O
bootable	O
disk	B-Application
image	I-Application
file	B-Operating_System
.	O
</s>
<s>
The	O
Linux	O
version	O
of	O
the	O
CDfs	B-Application
driver	B-Application
is	O
not	O
part	O
of	O
the	O
mainline	O
Linux	O
kernel	B-Operating_System
.	O
</s>
<s>
In	O
the	O
implementation	O
for	O
the	O
operating	B-General_Concept
system	I-General_Concept
Plan	B-Operating_System
9	I-Operating_System
from	I-Operating_System
Bell	I-Operating_System
Labs	I-Operating_System
,	O
cdfs	B-Application
is	O
a	O
server	O
that	O
runs	O
in	O
user	B-Operating_System
space	I-Operating_System
via	O
the	O
9P	B-Operating_System
protocol	I-Operating_System
.	O
</s>
<s>
It	O
represents	O
the	O
mounted	O
disc	O
as	O
a	O
directory	B-Application
of	O
files	O
named	O
by	O
track	O
number	O
.	O
</s>
<s>
Plan	B-Operating_System
9	I-Operating_System
's	O
CDfs	B-Application
can	O
also	O
write	O
to	O
the	O
disc	O
.	O
</s>
