<s>
GLtron	B-Application
is	O
a	O
3D	O
snake	B-Application
game	I-Application
based	O
on	O
the	O
light	O
cycle	O
portion	O
of	O
the	O
film	O
Tron	B-Language
.	O
</s>
<s>
The	O
game	O
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
and	O
has	O
been	O
ported	O
to	O
many	O
mobile	O
and	O
non-mobile	O
operating	O
systems	O
such	O
as	O
Windows	B-Application
,	O
MacOS	B-Application
,	O
Symbian	B-Operating_System
and	O
Android	B-Application
over	O
the	O
years	O
.	O
</s>
<s>
After	O
being	O
originally	O
a	O
private	O
university	O
project	O
by	O
Andreas	O
Umbach	O
in	O
June	O
1998	O
,	O
the	O
game	O
's	O
open-source	B-Application
development	I-Application
started	O
when	O
the	O
source	O
code	O
was	O
put	O
to	O
SourceForge	B-Application
around	O
1999	O
under	O
the	O
GPL-2.0-or-later	B-License
software	B-License
license	I-License
.	O
</s>
<s>
The	O
game	O
is	O
played	O
using	O
the	O
keyboard	B-Device
to	O
control	O
the	O
vehicle	O
and	O
the	O
mouse	B-Device
to	O
control	O
the	O
camera	O
position	O
,	O
players	O
can	O
out	O
ride	O
competitors	O
across	O
the	O
geometric	O
grid	O
.	O
</s>
<s>
In	O
2006	O
,	O
GLTron	B-Application
was	O
recommended	O
by	O
The	O
Mac	O
Observer	O
for	O
its	O
graphics	O
and	O
sound	O
,	O
considered	O
good	O
for	O
a	O
free	B-Application
software	I-Application
game	O
,	O
and	O
support	O
for	O
different	O
screen	O
resolutions	O
and	O
input	O
devices	O
.	O
</s>
<s>
Other	O
reviews	O
were	O
positive	O
too	O
,	O
for	O
instance	O
The	O
Linux	B-Application
Game	O
Tome	O
gave	O
4/5	O
stars	O
.	O
</s>
<s>
The	O
game	O
was	O
ported	O
to	O
multiple	B-Operating_System
systems	I-Operating_System
like	O
Linux	B-Application
,	O
Windows	B-Application
,	O
MacOS	B-Application
as	O
also	O
mobile	O
systems	O
that	O
have	O
support	O
for	O
OpenGL	B-Application
ES	I-Application
like	O
Symbian	B-Operating_System
,	O
Android	B-Application
,	O
and	O
as	O
also	O
the	O
OpenPandora	O
handheld	B-Application
.	O
</s>
<s>
Gltron	B-Application
was	O
downloaded	O
between	O
2000	O
and	O
2016	O
1,500,000	O
times	O
from	O
SourceForge	B-Application
alone	O
,	O
while	O
it	O
is	O
also	O
packaged	O
with	O
many	O
Linux	B-Application
distributions	I-Application
like	O
Debian	O
.	O
</s>
