<s>
Xinuos	O
OpenServer	B-Operating_System
,	O
previously	O
SCO	B-Operating_System
UNIX	I-Operating_System
and	O
SCO	B-Operating_System
Open	I-Operating_System
Desktop	I-Operating_System
(	O
SCO	B-Operating_System
ODT	I-Operating_System
)	O
,	O
is	O
a	O
closed	B-Application
source	I-Application
computer	B-General_Concept
operating	I-General_Concept
system	I-General_Concept
developed	O
by	O
Santa	O
Cruz	O
Operation	O
(	O
SCO	O
)	O
,	O
later	O
acquired	O
by	O
SCO	O
Group	O
,	O
and	O
now	O
owned	O
by	O
Xinuos	O
.	O
</s>
<s>
Early	O
versions	O
of	O
OpenServer	B-Operating_System
were	O
based	O
on	O
UNIX	B-Operating_System
System	I-Operating_System
V	I-Operating_System
,	O
while	O
the	O
later	O
OpenServer	B-Operating_System
10	O
is	O
based	O
on	O
FreeBSD	B-Operating_System
10	O
.	O
</s>
<s>
SCO	B-Operating_System
UNIX	I-Operating_System
was	O
the	O
successor	O
to	O
the	O
Santa	O
Cruz	O
Operation	O
's	O
variant	O
of	O
Microsoft	B-Application
Xenix	I-Application
,	O
derived	O
from	O
UNIX	B-Operating_System
System	I-Operating_System
V	I-Operating_System
Release	I-Operating_System
3.2	I-Operating_System
with	O
an	O
infusion	O
of	O
Xenix	B-Application
device	O
drivers	O
and	O
utilities	O
.	O
</s>
<s>
SCO	B-Operating_System
UNIX	I-Operating_System
System	O
V/386	O
Release	O
3.2.0	O
was	O
released	O
in	O
1989	O
,	O
as	O
the	O
commercial	O
successor	O
to	O
SCO	B-Application
Xenix	I-Application
.	O
</s>
<s>
The	O
base	O
operating	B-General_Concept
system	I-General_Concept
did	O
not	O
include	O
TCP/IP	B-Protocol
networking	O
or	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
graphics	O
;	O
these	O
were	O
available	O
as	O
optional	O
extra-cost	O
add-on	O
packages	O
.	O
</s>
<s>
Shortly	O
after	O
the	O
release	O
of	O
this	O
bare	O
OS	O
,	O
SCO	O
shipped	O
an	O
integrated	O
product	O
under	O
the	O
name	O
of	O
SCO	B-Operating_System
Open	I-Operating_System
Desktop	I-Operating_System
,	O
or	O
ODT	O
.	O
</s>
<s>
1994	O
saw	O
the	O
release	O
of	O
SCO	O
MPX	O
,	O
an	O
add-on	O
SMP	B-Operating_System
package	O
.	O
</s>
<s>
At	O
the	O
same	O
time	O
,	O
AT&T	O
completed	O
its	O
merge	O
of	O
Xenix	B-Application
,	O
BSD	B-Operating_System
,	O
SunOS	B-Operating_System
,	O
and	O
UNIX	B-Operating_System
System	I-Operating_System
V	I-Operating_System
Release	I-Operating_System
3	I-Operating_System
features	O
into	O
UNIX	B-Operating_System
System	I-Operating_System
V	I-Operating_System
Release	O
4	O
.	O
</s>
<s>
SCO	B-Operating_System
UNIX	I-Operating_System
remained	O
based	O
on	O
System	B-Operating_System
V	I-Operating_System
Release	I-Operating_System
3	I-Operating_System
,	O
but	O
eventually	O
added	O
home-grown	O
versions	O
of	O
most	O
of	O
the	O
features	O
of	O
Release	O
4	O
.	O
</s>
<s>
The	O
1992	O
releases	O
of	O
SCO	B-Operating_System
UNIX	I-Operating_System
3.2v4.0	O
and	O
Open	O
Desktop	O
2.0	O
added	O
support	O
for	O
long	O
file	O
names	O
and	O
symbolic	B-Application
links	I-Application
.	O
</s>
<s>
The	O
next	O
major	O
version	O
,	O
OpenServer	B-Operating_System
Release	O
5.0.0	O
,	O
released	O
in	O
1995	O
,	O
added	O
support	O
for	O
ELF	O
executables	O
and	O
dynamically	O
linked	O
shared	O
objects	O
,	O
and	O
made	O
many	O
kernel	O
structures	O
dynamic	O
.	O
</s>
<s>
SCO	B-Operating_System
OpenServer	I-Operating_System
5	O
,	O
released	O
in	O
1995	O
,	O
would	O
become	O
SCO	O
's	O
primary	O
product	O
and	O
serve	O
as	O
the	O
basis	O
for	O
products	O
like	O
PizzaNet	O
(	O
the	O
first	O
Internet-based	O
food	O
delivery	O
system	O
done	O
in	O
partnership	O
with	O
Pizza	O
Hut	O
)	O
and	O
SCO	O
Global	O
Access	O
,	O
an	O
Internet	O
gateway	O
server	O
based	O
on	O
Open	O
Desktop	O
Lite	O
.	O
</s>
<s>
Due	O
to	O
its	O
large	O
installed	O
base	O
,	O
SCO	B-Operating_System
OpenServer	I-Operating_System
5	O
continues	O
to	O
be	O
actively	O
maintained	O
by	O
SCO	O
with	O
major	O
updates	O
having	O
occurred	O
as	O
recently	O
as	O
September	O
2018	O
.	O
</s>
<s>
SCO	B-Operating_System
OpenServer	I-Operating_System
6	O
,	O
based	O
on	O
the	O
merging	O
of	O
AT&T	B-Operating_System
UNIX	I-Operating_System
System	B-Operating_System
V	I-Operating_System
Release	O
4.2MP	O
and	O
UnixWare	B-Operating_System
7	I-Operating_System
,	O
was	O
initially	O
released	O
by	O
The	O
SCO	O
Group	O
in	O
2005	O
.	O
</s>
<s>
This	O
merged	O
codebase	O
is	O
referred	O
to	O
as	O
UNIX	B-Operating_System
System	I-Operating_System
V	I-Operating_System
Release	O
5	O
(	O
SVR5	O
)	O
and	O
was	O
used	O
only	O
by	O
SCO	O
for	O
OpenServer	B-Operating_System
6	O
;	O
SVR5	O
is	O
not	O
used	O
by	O
any	O
other	O
major	O
developer	O
or	O
reseller	O
.	O
</s>
<s>
SCO	B-Operating_System
OpenServer	I-Operating_System
6	O
contains	O
the	O
UnixWare	B-Operating_System
7	I-Operating_System
's	O
SVR5	O
kernel	O
integrated	O
with	O
SCO	B-Operating_System
OpenServer	I-Operating_System
5	O
application	O
and	O
binary	O
compatibility	O
,	O
OpenServer	B-Operating_System
5	O
system	O
administration	O
,	O
and	O
OpenServer	B-Operating_System
5	O
user	O
environments	O
.	O
</s>
<s>
SCO	B-Operating_System
OpenServer	I-Operating_System
has	O
primarily	O
been	O
sold	O
into	O
the	O
small	O
and	O
medium	O
business	O
(	O
SMB	O
)	O
market	O
.	O
</s>
<s>
It	O
is	O
widely	O
used	O
in	O
small	O
offices	O
,	O
point	O
of	O
sale	O
(	O
POS	O
)	O
systems	O
,	O
replicated	O
sites	O
,	O
and	O
backoffice	O
database	B-Application
server	I-Application
deployments	O
.	O
</s>
<s>
Prominent	O
larger	O
SCO	B-Operating_System
OpenServer	I-Operating_System
customers	O
include	O
McDonald	O
's	O
,	O
Taco	O
Bell	O
,	O
Big	O
O	O
Tires	O
,	O
Pizza	O
Hut	O
,	O
Costco	O
pharmacy	O
,	O
NASDAQ	O
,	O
The	O
Toronto	O
Stock	O
Exchange	O
,	O
Banco	O
do	O
Brasil	O
,	O
many	O
banks	O
in	O
Russia	O
and	O
China	O
,	O
and	O
the	O
railway	O
system	O
of	O
India	O
.	O
</s>
<s>
SCO	O
purchased	O
the	O
right	O
to	O
distribute	O
the	O
UnixWare	B-Operating_System
system	O
and	O
its	O
System	B-Operating_System
V	I-Operating_System
Release	O
4	O
code	O
base	O
from	O
Novell	O
in	O
1995	O
.	O
</s>
<s>
SCO	O
was	O
eventually	O
able	O
to	O
re-use	O
some	O
code	O
from	O
that	O
version	O
of	O
UnixWare	B-Operating_System
in	O
later	O
releases	O
of	O
OpenServer	B-Operating_System
.	O
</s>
<s>
Until	O
Release	O
6	O
,	O
this	O
came	O
primarily	O
in	O
the	O
compilation	O
system	O
and	O
the	O
UDI	B-Application
driver	O
framework	O
and	O
the	O
USB	B-Protocol
subsystem	O
written	O
to	O
it	O
.	O
</s>
<s>
By	O
the	O
end	O
of	O
the	O
1990s	O
,	O
there	O
were	O
around	O
15,000	O
value-added	O
resellers	O
(	O
VARs	O
)	O
around	O
the	O
world	O
who	O
provided	O
solutions	O
for	O
customers	O
of	O
SCO	O
's	O
Unix	B-Application
systems	I-Application
.	O
</s>
<s>
SCO	O
announced	O
on	O
August	O
2	O
,	O
2000	O
,	O
that	O
it	O
would	O
sell	O
its	O
Server	O
Software	O
and	O
Services	O
Divisions	O
,	O
as	O
well	O
as	O
UnixWare	B-Operating_System
and	O
OpenServer	B-Operating_System
technologies	O
,	O
to	O
Caldera	O
Systems	O
,	O
Inc	O
.	O
</s>
<s>
The	O
SCO	O
Group	O
continued	O
the	O
development	O
and	O
maintenance	O
of	O
OpenServer	B-Operating_System
.	O
</s>
<s>
On	O
June	O
22	O
,	O
2005	O
,	O
OpenServer	B-Operating_System
6.0	O
was	O
released	O
,	O
codenamed	O
"	O
Legend	O
"	O
,	O
the	O
first	O
release	O
in	O
the	O
new	O
6.0.x	O
branch	O
.	O
</s>
<s>
SCO	B-Operating_System
OpenServer	I-Operating_System
6	O
is	O
based	O
on	O
the	O
UNIX	B-Operating_System
System	I-Operating_System
V	I-Operating_System
Release	O
5	O
kernel	O
,	O
a	O
merged	O
codebase	O
of	O
UNIX	B-Operating_System
System	I-Operating_System
V	I-Operating_System
Release	I-Operating_System
4.2MP	I-Operating_System
and	O
UnixWare	B-Operating_System
7	I-Operating_System
.	O
</s>
<s>
OpenServer	B-Operating_System
6.0	O
features	O
multi-threading	O
application	O
support	O
for	O
C	O
,	O
C++	O
,	O
and	O
Java	O
applications	O
through	O
the	O
POSIX	O
interface	O
.	O
</s>
<s>
OpenServer	B-Operating_System
6	O
features	O
kernel-level	O
threading	O
(	O
not	O
found	O
in	O
5.0.x	O
)	O
.	O
</s>
<s>
Some	O
improvements	O
over	O
OpenServer	B-Operating_System
5	O
include	O
improved	O
SMP	B-Operating_System
support	O
(	O
support	O
for	O
up	O
to	O
32	O
processors	O
)	O
,	O
support	O
for	O
files	O
over	O
a	O
terabyte	O
on	O
a	O
partition	O
(	O
larger	O
network	O
files	O
supported	O
through	O
NFSv3	O
)	O
,	O
better	O
file	O
system	O
performance	O
,	O
and	O
support	O
for	O
up	O
to	O
64GB	O
of	O
memory	O
.	O
</s>
<s>
OpenServer	B-Operating_System
6.0	O
maintains	O
backward-compatibility	O
for	O
applications	O
developed	O
for	O
Xenix	B-Application
286	I-Application
onwards	O
.	O
</s>
<s>
The	O
rights	O
to	O
OpenServer	B-Operating_System
,	O
as	O
well	O
as	O
UnixWare	B-Operating_System
,	O
were	O
acquired	O
by	O
UnXis	O
in	O
2011	O
,	O
which	O
was	O
later	O
renamed	O
Xinuos	O
.	O
</s>
<s>
In	O
June	O
2015	O
,	O
Xinuos	O
announced	O
OpenServer	B-Operating_System
10	O
,	O
which	O
is	O
based	O
on	O
the	O
FreeBSD	B-Operating_System
10	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
In	O
December	O
2015	O
,	O
Xinuos	O
released	O
"	O
definitive	O
"	O
versions	O
of	O
OpenServer	B-Operating_System
5	O
,	O
OpenServer	B-Operating_System
6	O
,	O
and	O
UnixWare	B-Operating_System
7	I-Operating_System
.	O
</s>
<s>
In	O
December	O
2017	O
,	O
Xinuos	O
released	O
"	O
Definitive	O
2018	O
"	O
versions	O
of	O
OpenServer	B-Operating_System
6	O
and	O
UnixWare	B-Operating_System
7	I-Operating_System
,	O
and	O
in	O
October	O
2018	O
OpenServer	B-Operating_System
5	O
Definitive	O
2018	O
was	O
released	O
.	O
</s>
<s>
However	O
,	O
by	O
2023	O
,	O
OpenServer	B-Operating_System
10	O
was	O
no	O
longer	O
listed	O
as	O
a	O
product	O
on	O
Xinuos	O
 '	O
home	O
page	O
,	O
implying	O
that	O
it	O
had	O
been	O
withdrawn	O
from	O
marketing	O
.	O
</s>
<s>
Version	O
Basis	O
Date	O
Codename	O
Editions/Notes	O
SCO	B-Operating_System
UNIX	I-Operating_System
System	O
V/386	O
SVR3.2.0	O
1989	O
Open	O
Desktop	O
1.0	O
SVR3.2.1	O
1990	O
Open	O
Desktop	O
1.1	O
SVR3.2v2.0	O
1991	O
Supplement	O
for	O
upgrade	O
to	O
3.2v2.1	O
SCO	B-Operating_System
UNIX	I-Operating_System
SVR3.2v4.0	O
1992	O
Open	O
Desktop	O
2.0	O
SVR3.2v4.1	O
1992	O
Phoenix	O
Desktop	B-General_Concept
System	I-General_Concept
,	O
Server	O
Open	O
Desktop/Server	O
3.0	O
SVR3.2v4.2	O
1994	O
Thunderbird	O
Open	O
Desktop	O
,	O
Open	O
Desktop	O
Lite	O
,	O
Open	B-Operating_System
Server	I-Operating_System
OpenServer	B-Operating_System
5.0	O
SVR3.2v5.0	O
1995	O
Everest	O
Desktop	B-General_Concept
System	I-General_Concept
,	O
Host	O
System	O
,	O
Enterprise	O
System	O
OpenServer	B-Operating_System
5.0.2	O
SVR3.2v5.0.2	O
1996	O
Tenzing	O
Desktop	B-General_Concept
System	I-General_Concept
,	O
Host	O
System	O
,	O
Enterprise	O
System	O
,	O
Internet	O
FastStart	O
OpenServer	B-Operating_System
5.0.4	O
SVR3.2v5.0.4	O
1997	O
Comet	O
Desktop	B-General_Concept
System	I-General_Concept
,	O
Host	O
System	O
,	O
Enterprise	O
System	O
OpenServer	B-Operating_System
5.0.5	O
SVR3.2v5.0.5	O
1999	O
Davenport	O
Host	O
System	O
,	O
Desktop	B-General_Concept
System	I-General_Concept
,	O
Enterprise	O
System	O
OpenServer	B-Operating_System
5.0.6	O
SVR3.2v5.0.6	O
2000	O
Freedom	O
Host	O
System	O
,	O
Desktop	B-General_Concept
System	I-General_Concept
,	O
Enterprise	O
System	O
OpenServer	B-Operating_System
5.0.7	O
SVR3.2v5.0.7	O
2003	O
Harvey	O
West	O
Host	O
System	O
,	O
Desktop	B-General_Concept
System	I-General_Concept
,	O
Enterprise	O
System	O
OpenServer	B-Operating_System
6.0	O
SVR5	O
2005	O
Legend	O
A	O
"	O
merge	O
"	O
of	O
UnixWare	B-Operating_System
7	I-Operating_System
and	O
OpenServer	B-Operating_System
5	O
OpenServer	B-Operating_System
5.0.7V	O
SVR3.2v5.0.7V	O
2009	O
OpenServer	B-Operating_System
5.0.7V	O
import	O
a	O
pre-installed	O
Virtual	O
Appliance/Machine	O
onto	O
the	O
VMware	O
hypervisor	O
.	O
</s>
<s>
OpenServer	B-Operating_System
10	O
FreeBSD	B-Operating_System
10	O
2015	O
10.0	O
First	O
release	O
based	O
on	O
FreeBSD	B-Operating_System
10	O
and	O
Xinuos	O
enhancements	O
OpenServer	B-Operating_System
6	O
Definitive	O
SVR5	O
2015	O
Definitive	O
Upwards	O
compatible	O
with	O
OpenServer	B-Operating_System
6	O
Definitive	O
2018	O
OpenServer	B-Operating_System
5	O
Definitive	O
SVR3.2v5	O
2015	O
Definitive	O
Upwards	O
compatible	O
with	O
OpenServer	B-Operating_System
5	O
Definitive	O
2018OpenServer	O
10.3FreeBSD	O
10.3201610.3Release	O
based	O
on	O
FreeBSD	B-Operating_System
&	O
Xinuos	O
enhancements	O
.	O
</s>
