<s>
Tremulous	B-Application
is	O
a	O
free	B-Application
and	O
open	B-Application
source	I-Application
asymmetric	O
team-based	O
first-person	O
shooter	O
with	O
real-time	O
strategy	O
elements	O
.	O
</s>
<s>
Being	O
a	O
cross-platform	B-Operating_System
development	O
project	O
the	O
game	O
is	O
available	O
for	O
Windows	B-Application
,	O
Linux	B-Application
,	O
and	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
Tremulous	B-Application
is	O
an	O
asymmetric	O
team-based	O
first-person	O
shooter	O
with	O
elements	O
of	O
real	O
time	O
strategy	O
.	O
</s>
<s>
Tremulous	B-Application
 '	O
development	O
by	O
the	O
Dark	O
Legion	O
group	O
commenced	O
in	O
early	O
2000	O
as	O
a	O
modification	O
for	O
the	O
commercial	O
computer	O
game	O
Quake	B-Application
III	I-Application
Arena	I-Application
.	O
</s>
<s>
The	O
gameplay	O
is	O
generally	O
inspired	O
by	O
the	O
Quake	B-Application
II	I-Application
modification	O
Gloom	O
,	O
which	O
also	O
features	O
alien	O
vs	O
human	O
teams	O
with	O
distinct	O
user	O
classes	O
.	O
</s>
<s>
Although	O
,	O
Tremulous	B-Application
shares	O
no	O
content	O
with	O
Gloom	O
or	O
other	O
similar	O
themed	O
games	O
from	O
around	O
the	O
same	O
time	O
.	O
</s>
<s>
Another	O
game	O
with	O
features	O
similar	O
to	O
Tremulous	B-Application
was	O
Natural	B-Application
Selection	I-Application
,	O
but	O
Tremulous	B-Application
developers	O
say	O
it	O
is	O
neither	O
based	O
on	O
it	O
nor	O
inspired	O
by	O
it	O
.	O
</s>
<s>
According	O
to	O
the	O
developers	O
,	O
development	O
on	O
the	O
game	O
began	O
long	O
before	O
NS	B-Application
became	O
publicly	O
available	O
.	O
</s>
<s>
Following	O
the	O
release	O
of	O
the	O
Quake	B-Application
III	I-Application
Arena	I-Application
source	O
code	O
under	O
the	O
GPL	B-License
on	O
August	O
19	O
,	O
2005	O
,	O
the	O
developers	O
decided	O
to	O
rework	O
Tremulous	B-Application
into	O
a	O
standalone	O
,	O
free	B-Application
and	O
open	B-Application
source	I-Application
game	O
.	O
</s>
<s>
Tremulous	B-Application
is	O
licensed	O
under	O
the	O
GPL	B-License
,	O
although	O
it	O
includes	O
code	O
from	O
other	O
projects	O
that	O
was	O
released	O
under	O
other	O
GPL-compatible	O
licenses	O
.	O
</s>
<s>
With	O
the	O
stable	O
version	O
1.1.0	O
released	O
on	O
March	O
31	O
,	O
2006	O
the	O
game	O
change	O
its	O
game	O
engine	O
to	O
ioquake3	B-Application
,	O
a	O
modified	O
id	B-Application
Tech	I-Application
3	I-Application
engine	O
.	O
</s>
<s>
White	O
of	O
the	O
ETPub	O
mod	O
for	O
Wolfenstein	B-Application
:	I-Application
Enemy	I-Application
Territory	I-Application
,	O
contributed	O
an	O
administrative	O
system	O
and	O
a	O
backported	O
client	O
that	O
were	O
soon	O
incorporated	O
into	O
the	O
official	O
Subversion	B-Application
repository	O
.	O
</s>
<s>
A	O
Tremulous	B-Application
continuation	B-Application
from	O
Dark	O
Legion	O
has	O
its	O
source	O
code	O
repository	O
migrated	O
to	O
GitHub	B-Application
and	O
is	O
not	O
under	O
active	O
development	O
(	O
last	O
commit	O
June	O
2016	O
)	O
.	O
</s>
<s>
Unvanquished	B-Application
is	O
a	O
Tremulous-based	O
FPS	O
with	O
another	O
engine	O
(	O
Daemon	O
)	O
,	O
which	O
was	O
first	O
released	O
publicly	O
in	O
2012	O
and	O
is	O
under	O
active	O
development	O
.	O
</s>
<s>
It	O
includes	O
many	O
original	O
maps	O
and	O
is	O
able	O
to	O
run	O
Tremulous	B-Application
maps	O
with	O
some	O
distributed	O
in	O
a	O
community	O
pack	O
.	O
</s>
<s>
Some	O
Unvanquished	B-Application
official	O
maps	O
were	O
community	O
maps	O
for	O
Tremulous	B-Application
.	O
</s>
<s>
The	O
game	O
is	O
based	O
on	O
a	O
Tremulous	B-Application
server	O
modification	O
which	O
was	O
worked	O
on	O
by	O
the	O
same	O
lead	O
developer	O
of	O
AAA	O
Games	O
,	O
but	O
due	O
to	O
licensing	O
problems	O
,	O
has	O
had	O
some	O
changes	O
away	O
from	O
its	O
previous	O
title	O
Tremulous	B-Application
2	O
and	O
concept	O
work	O
,	O
many	O
of	O
which	O
was	O
already	O
completed	O
.	O
</s>
<s>
Joe	O
Barr	O
of	O
NewsForge	O
called	O
Tremulous	B-Application
his	O
favorite	O
free	B-Application
software	I-Application
FPS	O
game	O
.	O
</s>
<s>
Tremulous	B-Application
was	O
voted	O
Player	O
's	O
Choice	O
Standalone	O
Game	O
of	O
the	O
Year	O
in	O
Mod	O
Database	O
's	O
Mod	O
of	O
the	O
Year	O
2006	O
competition	O
.	O
</s>
<s>
Tremulous	B-Application
later	O
came	O
in	O
first	O
in	O
a	O
"	O
Best	O
free	B-Application
game	O
based	O
on	O
GPL	B-License
Quake	O
source	O
?	O
"	O
</s>
<s>
At	O
the	O
beginning	O
of	O
2007	O
,	O
Tremulous	B-Application
also	O
took	O
first	O
place	O
in	O
the	O
Mod	O
Database	O
"	O
Mod	O
of	O
the	O
Year	O
"	O
2006	O
competition	O
under	O
the	O
category	O
of	O
"	O
Player	O
's	O
Choice	O
Standalone	O
Game	O
of	O
the	O
Year	O
"	O
as	O
well	O
as	O
honorable	O
mentions	O
in	O
"	O
Genre	O
Award	O
:	O
Action	O
"	O
and	O
"	O
Editor	O
's	O
Choice	O
Standalone	O
Game	O
of	O
the	O
Year	O
"	O
.	O
</s>
<s>
Tremulous	B-Application
was	O
also	O
mentioned	O
in	O
Games	B-Application
for	I-Application
Windows	I-Application
(	O
formerly	O
Computer	O
Gaming	O
World	O
)	O
:	O
101	O
Free	B-Application
Games	O
Issue	O
for	O
2007	O
.	O
</s>
<s>
Tremulous	B-Application
was	O
selected	O
in	O
March	O
2010	O
as	O
"	O
HotPick	O
"	O
by	O
Linux	B-Application
Format	O
.	O
</s>
