<s>
Wolfenstein	B-Application
:	I-Application
Enemy	I-Application
Territory	I-Application
is	O
a	O
free	B-License
and	I-License
open-source	I-License
multiplayer	O
first-person	O
shooter	O
video	O
game	O
within	O
the	O
Wolfenstein	B-Application
series	O
.	O
</s>
<s>
It	O
was	O
originally	O
planned	O
to	O
be	O
released	O
as	O
a	O
commercial	O
expansion	O
pack	O
to	O
Return	B-Application
to	I-Application
Castle	I-Application
Wolfenstein	I-Application
and	O
later	O
as	O
a	O
standalone	O
game	O
.	O
</s>
<s>
However	O
,	O
due	O
to	O
problems	O
with	O
the	O
single-player	O
aspect	O
,	O
the	O
multiplayer	O
portion	O
was	O
released	O
on	O
29	O
May	O
2003	O
as	O
a	O
freeware	B-License
standalone	O
game	O
.	O
</s>
<s>
The	O
game	O
uses	O
a	O
modified	O
Return	B-Application
to	I-Application
Castle	I-Application
Wolfenstein	I-Application
engine	O
,	O
itself	O
being	O
a	O
heavily	O
modified	O
id	B-Application
Tech	I-Application
3	I-Application
engine	O
,	O
which	O
has	O
been	O
open	B-Application
source	I-Application
since	O
2005	O
.	O
</s>
<s>
As	O
of	O
the	O
first	O
day	O
of	O
the	O
August	O
2010	O
QuakeCon	O
,	O
the	O
entire	O
source	O
code	O
was	O
released	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
v3.0	I-License
or	I-License
later	I-License
.	O
</s>
<s>
On	O
April	O
26	O
,	O
2022	O
,	O
the	O
game	O
was	O
released	O
on	O
Steam	B-Application
,	O
and	O
on	O
October	O
20	O
,	O
2022	O
on	O
gog.com	O
.	O
</s>
<s>
A	O
commercially	O
released	O
follow-up	O
,	O
Enemy	B-Application
Territory	I-Application
:	I-Application
Quake	I-Application
Wars	I-Application
,	O
was	O
developed	O
by	O
Splash	O
Damage	O
.	O
</s>
<s>
Wolfenstein	B-Application
:	I-Application
Enemy	I-Application
Territory	I-Application
is	O
an	O
online	O
multiplayer	O
game	O
,	O
wherein	O
the	O
players	O
interact	O
with	O
each	O
other	O
over	O
a	O
network	O
,	O
in	O
two	O
teams	O
(	O
Allies	O
and	O
Axis	O
)	O
to	O
defend	O
or	O
destroy	O
mission	O
objectives	O
.	O
</s>
<s>
The	O
game	O
is	O
playable	O
over	O
the	O
Internet	O
or	O
a	O
Local	B-General_Concept
Area	I-General_Concept
Network	I-General_Concept
.	O
</s>
<s>
In	O
public	O
games	O
,	O
PunkBuster	B-Application
used	O
to	O
protect	O
the	O
game	O
,	O
however	O
its	O
developer	O
,	O
EvenBalance	O
,	O
discontinued	O
support	O
for	O
the	O
game	O
in	O
October	O
2011	O
.	O
</s>
<s>
In	O
Stopwatch	O
Mode	O
(	O
most	O
common	O
for	O
locked	O
or	O
LAN	B-General_Concept
servers	O
)	O
two	O
teams	O
—	O
most	O
common	O
setups	O
:	O
6vs6	O
or	O
3vs3	O
—	O
will	O
play	O
the	O
same	O
map	O
twice	O
,	O
once	O
on	O
each	O
side	O
and	O
the	O
winner	O
is	O
the	O
team	O
with	O
the	O
fastest	O
offense	O
(	O
it	O
can	O
be	O
a	O
tie	O
when	O
both	O
teams	O
defense	O
manage	O
to	O
keep	O
the	O
offense	O
from	O
completing	O
the	O
objectives	O
until	O
time	O
runs	O
out	O
(	O
commonly	O
known	O
as	O
a	O
"	O
full	O
hold	O
"	O
)	O
)	O
.	O
</s>
<s>
Based	O
on	O
the	O
source	O
code	O
of	O
Wolfenstein	B-Application
:	I-Application
Enemy	I-Application
Territory	I-Application
,	O
ET	O
:	O
Legacy	O
(	O
ETL	O
)	O
is	O
an	O
open	B-Application
source	I-Application
project	O
aiming	O
to	O
create	O
a	O
modernized	O
client	O
and	O
server	O
while	O
still	O
being	O
as	O
compatible	O
as	O
possible	O
with	O
the	O
original	O
game	O
version	O
,	O
ET	O
2.60b	O
,	O
and	O
its	O
game	O
mods	O
.	O
</s>
