<s>
The	O
Quake	B-Application
II	I-Application
engine'''	O
is	O
a	O
game	O
engine	O
developed	O
by	O
id	O
Software	O
for	O
use	O
in	O
their	O
1997	O
first-person	O
shooter	O
Quake	B-Application
II	I-Application
.	O
</s>
<s>
It	O
is	O
the	O
successor	O
to	O
the	O
Quake	B-Application
engine	I-Application
.	O
</s>
<s>
Since	O
its	O
release	O
,	O
the	O
Quake	B-Application
II	I-Application
engine	I-Application
has	O
been	O
licensed	O
for	O
use	O
in	O
several	O
other	O
games	O
.	O
</s>
<s>
One	O
of	O
the	O
engine	O
's	O
most	O
notable	O
features	O
was	O
out-of-the-box	O
support	O
for	O
hardware-accelerated	O
graphics	O
,	O
specifically	O
OpenGL	B-Application
,	O
along	O
with	O
the	O
traditional	O
software	O
renderer	O
.	O
</s>
<s>
This	O
allowed	O
both	O
software	O
and	O
OpenGL	B-Application
renderers	O
,	O
which	O
were	O
selected	O
by	O
loading	O
and	O
unloading	O
separate	O
libraries	O
.	O
</s>
<s>
Since	O
they	O
were	O
compiled	O
for	O
specific	O
platforms	O
,	O
instead	O
of	O
an	O
interpreter	B-Application
,	O
they	O
could	O
run	O
faster	O
than	O
Quakes	B-Application
solution	O
,	O
which	O
was	O
to	O
run	O
the	O
game	O
logic	O
(	O
QuakeC	B-Application
)	O
in	O
a	O
limited	O
interpreter	B-Application
.	O
</s>
<s>
The	O
level	O
environments	O
were	O
lit	O
using	O
lightmaps	B-Data_Structure
,	O
a	O
method	O
in	O
which	O
light	O
data	O
for	O
each	O
surface	O
is	O
precalculated	O
(	O
this	O
time	O
,	O
via	O
a	O
radiosity	O
method	O
)	O
and	O
stored	O
as	O
an	O
image	O
,	O
which	O
is	O
then	O
used	O
to	O
determine	O
the	O
lighting	O
intensity	O
each	O
3D	O
model	O
should	O
receive	O
,	O
but	O
not	O
its	O
direction	O
.	O
</s>
<s>
id	O
Software	O
released	O
the	O
source	O
code	O
on	O
December	O
22	O
,	O
2001	O
under	O
the	O
terms	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
v2.0	I-License
or	I-License
later	I-License
.	O
</s>
<s>
Jake2	O
is	O
a	O
Java	B-Language
port	O
of	O
the	O
Quake	B-Application
II	I-Application
engine	I-Application
's	O
GPL	B-License
release	O
.	O
</s>
<s>
It	O
has	O
since	O
been	O
used	O
by	O
Sun	O
as	O
an	O
example	O
of	O
Java	B-Application
Web	I-Application
Start	I-Application
capabilities	O
for	O
games	O
distribution	O
over	O
the	O
Internet	O
.	O
</s>
<s>
In	O
2006	O
,	O
it	O
was	O
used	O
to	O
experiment	O
playing	O
3D	O
games	O
with	O
eye	B-General_Concept
tracking	I-General_Concept
.	O
</s>
<s>
The	O
performance	O
of	O
Jake2	O
is	O
on	O
par	O
with	O
the	O
original	O
C	B-Language
version	O
.	O
</s>
<s>
Yamagi	O
Quake	B-Application
II	I-Application
is	O
a	O
port	O
of	O
Quake	B-Application
II	I-Application
to	O
modern	O
systems	O
which	O
aims	O
to	O
preserve	O
the	O
original	O
gameplay	O
.	O
</s>
<s>
vkQuake2	O
is	O
the	O
original	O
Quake	O
II''	O
engine	O
with	O
additional	O
Vulkan	B-Application
renderer	O
created	O
by	O
Krzysztof	O
Kondrak	O
,	O
a	O
programmer	O
from	O
Poland	O
.	O
</s>
