<s>
USENIX	B-Operating_System
is	O
an	O
American	O
501(c )	O
(	O
3	O
)	O
nonprofit	O
membership	O
organization	O
based	O
in	O
Berkeley	O
,	O
California	O
and	O
founded	O
in	O
1975	O
that	O
supports	O
advanced	O
computing	O
systems	O
and	O
operating	B-General_Concept
system	I-General_Concept
(	O
OS	O
)	O
research	O
.	O
</s>
<s>
USENIX	B-Operating_System
was	O
established	O
in	O
1975	O
under	O
the	O
name	O
"	O
Unix	B-Application
Users	O
Group	O
,	O
"	O
focusing	O
primarily	O
on	O
the	O
study	O
and	O
development	O
of	O
the	O
Unix	B-Application
OS	O
family	O
and	O
similar	O
systems	O
.	O
</s>
<s>
In	O
June	O
1977	O
,	O
a	O
lawyer	O
from	O
AT&T	O
Corporation	O
informed	O
the	O
group	O
that	O
they	O
could	O
not	O
use	O
the	O
word	O
"	O
Unix	B-Application
"	O
in	O
their	O
name	O
as	O
it	O
was	O
a	O
trademark	O
of	O
Western	O
Electric	O
(	O
the	O
manufacturing	O
arm	O
of	O
AT&T	O
until	O
1995	O
)	O
,	O
which	O
led	O
to	O
the	O
change	O
of	O
name	O
to	O
USENIX	B-Operating_System
.	O
</s>
<s>
It	O
has	O
since	O
grown	O
into	O
a	O
respected	O
organization	O
among	O
practitioners	O
,	O
developers	O
,	O
and	O
researchers	O
of	O
computer	B-General_Concept
operating	I-General_Concept
systems	I-General_Concept
more	O
generally	O
.	O
</s>
<s>
USENIX	B-Operating_System
was	O
started	O
as	O
a	O
technical	O
organization	O
.	O
</s>
<s>
As	O
commercial	O
interest	O
grew	O
,	O
a	O
number	O
of	O
separate	O
groups	O
started	O
in	O
parallel	O
,	O
most	O
notably	O
the	O
Software	B-Device
Tools	I-Device
Users	I-Device
Group	I-Device
(	O
STUG	O
)	O
,	O
a	O
technical	O
adjunct	O
for	O
Unix-like	O
tools	O
and	O
interface	O
on	O
non-Unix	O
operating	O
systems	O
,	O
and	O
/usr/group	O
,	O
a	O
commercially	O
oriented	O
user	O
group	O
.	O
</s>
<s>
USENIX	B-Operating_System
's	O
founding	O
President	O
was	O
Lou	O
Katz	O
.	O
</s>
<s>
USENIX	B-Operating_System
hosts	O
numerous	O
conferences	O
and	O
symposia	O
each	O
year	O
,	O
including	O
:	O
</s>
