<s>
Hovertank	B-Application
3D	I-Application
,	O
also	O
known	O
under	O
a	O
variety	O
of	O
other	O
names	O
(	O
Hovertank	O
or	O
Hovertank	B-Application
One	I-Application
)	O
,	O
is	O
a	O
vehicular	O
combat	O
game	O
developed	O
by	O
id	O
Software	O
and	O
published	O
by	O
Softdisk	O
in	O
April	O
1991	O
.	O
</s>
<s>
Hovertank	B-Application
3D	I-Application
is	O
set	O
during	O
a	O
nuclear	O
war	O
.	O
</s>
<s>
In	O
Hovertank	B-Application
3D	I-Application
,	O
the	O
player	O
controls	O
Brick	O
Sledge	O
,	O
a	O
mercenary	B-Application
hired	O
by	O
an	O
unknown	O
organization	O
(	O
referred	O
to	O
by	O
the	O
game	O
as	O
the	O
"	O
UFA	O
"	O
)	O
to	O
rescue	O
people	O
from	O
cities	O
under	O
the	O
threat	O
of	O
nuclear	O
attack	O
(	O
largely	O
political	O
activists	O
or	O
scientists	O
)	O
,	O
both	O
by	O
the	O
government	O
and	O
by	O
large	O
corporations	O
.	O
</s>
<s>
The	O
engine	O
written	O
for	O
this	O
game	O
was	O
expanded	O
upon	O
with	O
texture	O
mapping	O
to	O
make	O
Catacomb	B-Application
3-D	I-Application
,	O
and	O
then	O
later	O
still	O
with	O
raycasting	B-Algorithm
for	O
Wolfenstein	B-Application
3D	I-Application
.	O
</s>
<s>
The	O
credits	O
are	O
John	O
Carmack	O
and	O
John	O
Romero	O
as	O
programmers	B-Application
,	O
Tom	O
Hall	O
as	O
game	O
designer	O
and	O
Adrian	O
Carmack	O
as	O
video	O
game	O
artist	O
.	O
</s>
<s>
The	O
source	O
code	O
to	O
the	O
game	O
,	O
owned	O
by	O
Flat	O
Rock	O
Software	O
,	O
was	O
released	O
in	O
June	O
2014	O
under	O
GNU	B-License
GPL-2.0-or-later	I-License
in	O
a	O
manner	O
similar	O
those	O
done	O
by	O
id	O
and	O
partners	O
.	O
</s>
<s>
Hovertank	B-Application
3D	I-Application
is	O
a	O
landmark	O
3D	O
game	O
.	O
</s>
<s>
Other	O
3D	O
titles	O
at	O
the	O
time	O
,	O
such	O
as	O
flight	B-Application
simulators	I-Application
and	O
other	O
games	O
(	O
such	O
as	O
Alpha	B-Application
Waves	I-Application
)	O
that	O
had	O
more	O
detailed	O
environments	O
,	O
were	O
noticeably	O
slower	O
.	O
</s>
<s>
A	O
similar	O
engine	O
was	O
used	O
by	O
MIDI	B-Application
Maze	I-Application
for	O
the	O
Atari	B-Device
ST	I-Device
in	O
1987	O
and	O
Wayout	B-Application
for	O
the	O
Atari	B-Device
8-bit	I-Device
family	I-Device
from	O
1982	O
.	O
</s>
