<s>
The	O
Open	B-Library
Sound	I-Library
System	I-Library
(	O
OSS	O
)	O
is	O
an	O
interface	O
for	O
making	O
and	O
capturing	O
sound	O
in	O
Unix	B-Application
and	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
It	O
is	O
based	O
on	O
standard	O
Unix	B-Application
devices	B-Application
system	B-Operating_System
calls	I-Operating_System
(	O
i.e.	O
</s>
<s>
POSIX	O
read	B-Language
,	O
write	B-Language
,	O
ioctl	B-Operating_System
,	O
etc	O
.	O
)	O
.	O
</s>
<s>
The	O
term	O
also	O
sometimes	O
refers	O
to	O
the	O
software	O
in	O
a	O
Unix	B-Application
kernel	O
that	O
provides	O
the	O
OSS	O
interface	O
;	O
it	O
can	O
be	O
thought	O
of	O
as	O
a	O
device	B-Application
driver	I-Application
(	O
or	O
a	O
collection	O
of	O
device	B-Application
drivers	I-Application
)	O
for	O
sound	B-Device
controller	I-Device
hardware	O
.	O
</s>
<s>
OSS	O
was	O
created	O
by	O
Hannu	O
Savolainen	O
and	O
is	O
distributed	O
under	O
four	B-License
license	I-License
options	I-License
,	O
three	O
of	O
which	O
are	O
free	B-License
software	I-License
licences	I-License
,	O
thus	O
making	O
OSS	O
free	B-Application
software	I-Application
.	O
</s>
<s>
The	O
API	O
is	O
designed	O
to	O
use	O
the	O
traditional	B-Application
Unix	I-Application
framework	O
of	O
open( )	O
,	O
read( )	O
,	O
write( )	O
,	O
and	O
ioctl( )	O
,	O
via	O
device	B-Application
files	I-Application
.	O
</s>
<s>
For	O
instance	O
,	O
the	O
default	O
device	O
for	O
sound	O
input	O
and	O
output	O
is	O
/dev/dsp	B-Library
.	O
</s>
<s>
OSS	O
implements	O
the	O
/dev/audio	O
interface	O
.	O
</s>
<s>
On	O
Linux	B-Application
,	O
OSS4	B-Library
is	O
also	O
able	O
to	O
emulate	O
ALSA	B-Application
,	O
its	O
open-source	O
replacement	O
.	O
</s>
<s>
OSS	O
was	O
originally	O
"	O
VoxWare	O
"	O
,	O
a	O
Linux	B-Application
kernel	O
sound	O
driver	O
by	O
Hannu	O
Savolainen	O
.	O
</s>
<s>
Savolainen	O
made	O
the	O
code	O
available	O
under	O
free	B-License
software	I-License
licenses	I-License
,	O
GPL	B-License
for	O
Linux	B-Application
and	O
BSD	B-Operating_System
for	O
BSD	B-Operating_System
distributions	O
.	O
</s>
<s>
Between	O
1993	O
and	O
1997	O
,	O
OSS	O
was	O
the	O
sole	O
choice	O
of	O
sound	O
system	O
in	O
FreeBSD	B-Operating_System
and	O
Linux	B-Application
.	O
</s>
<s>
This	O
was	O
changed	O
when	O
Luigi	O
Rizzo	O
wrote	O
a	O
new	O
"	O
pcm	O
"	O
driver	O
for	O
FreeBSD	B-Operating_System
in	O
1997	O
,	O
and	O
when	O
Jaroslav	B-Application
Kysela	I-Application
started	O
Advanced	B-Application
Linux	I-Application
Sound	I-Application
Architecture	I-Application
in	O
1998	O
.	O
</s>
<s>
In	O
2002	O
,	O
Savolainen	O
was	O
contracted	O
by	O
the	O
company	O
4Front	O
Technologies	O
and	O
made	O
the	O
upcoming	O
OSS	O
4	O
,	O
which	O
includes	O
support	O
for	O
newer	O
sound	O
devices	B-Application
and	O
improvements	O
,	O
proprietary	B-Application
.	O
</s>
<s>
In	O
response	O
,	O
the	O
Linux	B-Application
community	O
abandoned	O
the	O
OSS/free	O
implementation	O
included	O
in	O
the	O
kernel	O
and	O
development	O
effort	O
switched	O
to	O
the	O
replacement	O
Advanced	B-Application
Linux	I-Application
Sound	I-Application
Architecture	I-Application
(	O
ALSA	B-Application
)	O
.	O
</s>
<s>
FreeBSD	B-Operating_System
by	O
this	O
time	O
had	O
switched	O
to	O
a	O
"	O
newpcm	O
"	O
project	O
started	O
in	O
1999	O
and	O
was	O
not	O
affected	O
.	O
</s>
<s>
In	O
July	O
2007	O
,	O
4Front	O
Technologies	O
released	O
sources	O
for	O
OSS	O
under	O
CDDL-1.0	B-Application
for	O
OpenSolaris	B-Operating_System
and	O
GPL-2.0-only	B-License
for	O
Linux	B-Application
.	O
</s>
<s>
Drivers	O
for	O
some	O
soundcards	B-Device
remained	O
closed-source	B-Application
and	O
were	O
not	O
included	O
in	O
the	O
release	O
.	O
</s>
<s>
In	O
January	O
2008	O
,	O
4Front	O
Technologies	O
released	O
OSS	O
for	O
FreeBSD	B-Operating_System
(	O
and	O
other	O
BSD	B-Operating_System
systems	O
)	O
under	O
the	O
BSD-2-Clause	B-Operating_System
.	O
</s>
<s>
OSS4	B-Library
now	O
exists	O
mostly	O
as	O
a	O
standalone	O
piece	O
of	O
software	O
,	O
not	O
integrated	O
into	O
the	O
kernel	O
source	O
code	O
.	O
</s>
<s>
The	O
exception	O
is	O
Solaris	B-Application
and	O
OpenSolaris	B-Operating_System
,	O
which	O
use	O
a	O
fork	O
of	O
OSS4	B-Library
called	O
Boomer	O
.	O
</s>
<s>
It	O
combines	O
the	O
OSS4	B-Library
framework	O
(	O
audio	O
and	O
mixer	O
)	O
together	O
with	O
Sun	O
's	O
earlier	O
SADA	O
(	O
/dev/audio	O
)	O
API	O
.	O
</s>
<s>
Although	O
Linux	B-Application
distributions	O
such	O
as	O
Ubuntu	B-Operating_System
made	O
OSS4	B-Library
available	O
as	O
a	O
software	O
package	O
after	O
it	O
was	O
made	O
free	B-Application
software	I-Application
,	O
they	O
have	O
chosen	O
to	O
ignore	O
any	O
bugs	O
filed	O
against	O
these	O
packages	O
.	O
</s>
<s>
NetBSD	B-Device
's	O
documentation	O
describes	O
it	O
as	O
"	O
the	O
preferred	O
API	O
in	O
FreeBSD	B-Operating_System
and	O
Solaris	B-Application
"	O
.	O
</s>
<s>
FreeBSD	B-Operating_System
contains	O
an	O
independently	O
developed	O
implementation	O
of	O
the	O
OSS	O
API	O
,	O
which	O
includes	O
,	O
among	O
other	O
things	O
,	O
in-kernel	O
resampling	O
,	O
mixing	O
(	O
vchans	O
)	O
,	O
equalizer	O
,	O
surround	O
sound	O
,	O
and	O
independent	O
volume	O
control	O
for	O
each	O
application	O
.	O
</s>
<s>
It	O
gradually	O
evolved	O
from	O
the	O
"	O
newpcm	O
"	O
replacement	O
written	O
in	O
1999	O
and	O
caught	O
up	O
with	O
OSS4	B-Library
API	O
around	O
2005	O
.	O
</s>
<s>
NetBSD	B-Device
supports	O
a	O
compatibility	O
mode	O
for	O
the	O
OSS	O
API	O
,	O
by	O
providing	O
the	O
soundcard.h	O
header	O
file	O
and	O
the	O
libossaudio	O
library	O
,	O
which	O
internally	O
operate	O
using	O
the	O
native	O
Sun-like	O
audio	O
interface	O
.	O
</s>
<s>
The	O
replacement	O
was	O
first	O
seen	O
in	O
NetBSD	B-Device
1.3	O
of	O
1998	O
.	O
</s>
<s>
Linux	B-Application
had	O
,	O
as	O
aforementioned	O
,	O
switched	O
to	O
Advanced	B-Application
Linux	I-Application
Sound	I-Application
Architecture	I-Application
since	O
2003	O
(	O
kernel	O
2.6	O
)	O
.	O
</s>
<s>
ALSA	B-Application
provides	O
an	O
optional	O
,	O
in-kernel	O
,	O
OSS	O
emulation	O
mode	O
that	O
appears	O
to	O
programs	O
as	O
if	O
it	O
were	O
OSS	O
.	O
</s>
<s>
ALSA	B-Application
also	O
has	O
a	O
aoss	O
userspace	O
program	O
that	O
works	O
by	O
intercepting	O
systems	O
calls	O
directed	O
to	O
the	O
OSS	O
device	B-Application
files	I-Application
.	O
</s>
<s>
Supported	O
players	O
include	O
Winamp	B-Application
,	O
Windows	B-Device
Media	I-Device
Player	I-Device
(	O
9	O
or	O
later	O
)	O
,	O
musicmatch	O
,	O
Sonique	O
,	O
Foobar2000	B-Application
,	O
JetAudio	B-Application
,	O
XMMS	B-Language
.	O
</s>
<s>
It	O
is	O
ported	O
to	O
Windows	O
and	O
Linux	B-Application
platforms	O
.	O
</s>
<s>
Unlike	O
the	O
OSS	O
,	O
it	O
is	O
shareware	B-License
.	O
</s>
<s>
OSS	O
both	O
as	O
API	O
and	O
as	O
software	O
has	O
been	O
criticized	O
by	O
some	O
developers	O
,	O
such	O
as	O
Paul	O
Davis	O
(	O
of	O
JACK	B-Application
Audio	I-Application
Connection	I-Application
Kit	I-Application
)	O
and	O
Lennart	O
Poettering	O
(	O
of	O
competing	O
PulseAudio	B-Library
)	O
.	O
</s>
<s>
Most	O
of	O
these	O
criticisms	O
were	O
either	O
specific	O
to	O
the	O
Linux	B-Application
implementation	O
and	O
not	O
to	O
the	O
OSS	O
API	O
itself	O
,	O
or	O
have	O
been	O
addressed	O
in	O
OSS	O
version	O
4	O
.	O
</s>
