<s>
Red	B-Application
Eclipse	I-Application
is	O
an	O
open-source	O
first-person	O
shooter	O
that	O
is	O
forked	B-Application
from	O
Cube	B-Application
2	I-Application
:	I-Application
Sauerbraten	I-Application
.	O
</s>
<s>
The	O
game	O
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
,	O
released	O
under	O
the	O
zlib	B-License
license	I-License
,	O
and	O
developed	O
by	O
an	O
open	O
community	O
of	O
contributors	O
.	O
</s>
<s>
Red	B-Application
Eclipse	I-Application
is	O
a	O
multiplayer	O
first-person	O
arena	O
shooter	O
,	O
similar	O
to	O
Cube	B-Application
2	I-Application
:	I-Application
Sauerbraten	I-Application
,	O
with	O
a	O
style	O
of	O
play	O
comparable	O
to	O
Quake	B-Application
III	I-Application
Arena	I-Application
or	O
Unreal	B-Operating_System
Tournament	I-Operating_System
.	O
</s>
<s>
Game	O
modes	O
include	O
:	O
Deathmatch	O
(	O
kill	O
to	O
score	O
)	O
,	O
Capture	B-Application
the	I-Application
Flag	I-Application
,	O
Defend	O
and	O
Control	O
(	O
players	O
must	O
secure	O
control	O
points	O
to	O
win	O
)	O
,	O
Bomber	O
Ball	O
(	O
a	O
bomb	O
must	O
be	O
brought	O
into	O
the	O
enemy	O
goal	O
before	O
it	O
explodes	O
)	O
,	O
Race	O
(	O
players	O
compete	O
for	O
the	O
number	O
of	O
laps	O
)	O
,	O
as	O
well	O
as	O
online	O
cooperative	O
map	O
editing	O
.	O
</s>
<s>
Unlike	O
Cube	O
2	O
,	O
Red	B-Application
Eclipse	I-Application
features	O
parkour	O
movement	O
,	O
such	O
as	O
vaulting	O
or	O
running	O
along	O
walls	O
.	O
</s>
<s>
Red	B-Application
Eclipse	I-Application
was	O
branched	O
from	O
the	O
defunct	O
Blood	O
Frontier	O
project	O
,	O
itself	O
a	O
fork	B-Application
of	O
Cube	B-Application
2	I-Application
:	I-Application
Sauerbraten	I-Application
that	O
began	O
development	O
in	O
2007	O
.	O
</s>
<s>
The	O
first	O
stable	O
release	O
of	O
Red	B-Application
Eclipse	I-Application
,	O
version	O
1.0	O
(	O
"	O
Ides	O
Edition	O
"	O
)	O
,	O
debuted	O
on	O
March	O
15	O
,	O
2011	O
.	O
</s>
<s>
The	O
game	O
engine	O
is	O
written	O
in	O
C++	B-Language
and	O
uses	O
SDL	B-Operating_System
with	O
OpenGL	B-Application
as	O
its	O
cross-platform	O
graphics	O
API	O
.	O
</s>
<s>
It	O
builds	O
and	O
expands	O
upon	O
established	O
concepts	O
of	O
Cube	O
2	O
,	O
and	O
uses	O
the	O
same	O
octree	B-Data_Structure
geometry	O
model	O
to	O
enable	O
real-time	O
,	O
WYSIWYG	B-Application
editing	O
.	O
</s>
<s>
Red	B-Application
Eclipse	I-Application
1.3	O
in	O
2012	O
introduced	O
two	O
new	O
modes	O
:	O
"	O
King	O
of	O
the	O
Hill	O
"	O
and	O
"	O
Coop	O
"	O
.	O
</s>
<s>
Version	O
1.6	O
,	O
released	O
on	O
December	O
21	O
,	O
2017	O
and	O
dubbed	O
"	O
Sunset	O
Edition	O
"	O
,	O
was	O
the	O
last	O
version	O
to	O
use	O
the	O
old	O
rendering	O
engine	O
,	O
before	O
the	O
game	O
started	O
using	O
parts	O
of	O
the	O
engine	O
of	O
Tesseract	O
(	O
another	O
fork	B-Application
of	O
Cube	O
2	O
)	O
for	O
the	O
next	O
major	O
release	O
.	O
</s>
<s>
Tesseract	O
's	O
graphical	O
improvements	O
allowed	O
Red	B-Application
Eclipse	I-Application
to	O
use	O
more	O
advanced	O
rendering	O
and	O
lighting	O
techniques	O
—	O
most	O
notably	O
deferred	O
shading	O
,	O
better	O
shadow-mapping	O
,	O
and	O
support	O
for	O
reflection	O
and	O
refraction	O
.	O
</s>
<s>
Red	B-Application
Eclipse	I-Application
2.0	O
(	O
"	O
Jupiter	O
Edition	O
"	O
)	O
,	O
the	O
first	O
version	O
to	O
use	O
the	O
new	O
engine	O
,	O
was	O
released	O
on	O
Steam	O
in	O
December	O
2019	O
.	O
</s>
<s>
In	O
2013	O
,	O
Red	B-Application
Eclipse	I-Application
was	O
used	O
by	O
researchers	O
of	O
the	O
University	O
of	O
Illinois	O
at	O
Urbana-Champaign	O
and	O
Microsoft	O
Research	O
for	O
the	O
creation	O
of	O
IllumiRoom	B-Application
,	O
a	O
project	O
to	O
create	O
an	O
augmented	O
television	O
screen	O
with	O
projectors	O
.	O
</s>
<s>
The	O
researchers	O
noted	O
in	O
their	O
IllumiRoom	B-Application
paper	O
for	O
the	O
CHI	O
2013	O
that	O
access	O
to	O
Red	B-Application
Eclipse	I-Application
's	O
source	O
code	O
enabled	O
a	O
"	O
rich	O
,	O
interactive	O
experience	O
"	O
.	O
</s>
