<s>
0	B-Application
A.D.	I-Application
is	O
a	O
free	B-License
and	I-License
open-source	I-License
real-time	O
strategy	O
video	O
game	O
under	O
development	O
by	O
Wildfire	O
Games	O
.	O
</s>
<s>
The	O
game	O
is	O
cross-platform	B-Operating_System
,	O
playable	O
on	O
Windows	B-Application
,	O
macOS	B-Application
,	O
Linux	B-Application
,	O
FreeBSD	B-Operating_System
,	O
and	O
OpenBSD	B-Operating_System
.	O
</s>
<s>
It	O
is	O
composed	O
entirely	O
of	O
free	B-Application
software	I-Application
and	O
free	O
media	O
,	O
using	O
the	O
GNU	O
GPLv2	O
(	O
or	O
later	O
)	O
license	O
for	O
the	O
game	O
engine	O
source	O
code	O
,	O
and	O
the	O
CC	O
BY-SA	O
license	O
for	O
the	O
game	O
art	O
and	O
music	O
.	O
</s>
<s>
0	B-Application
A.D.	I-Application
features	O
the	O
traditional	O
real-time	O
strategy	O
gameplay	O
components	O
of	O
building	O
a	O
base	O
,	O
developing	O
an	O
economy	O
,	O
training	O
an	O
army	O
,	O
engaging	O
in	O
combat	O
,	O
and	O
researching	O
new	O
technologies	O
.	O
</s>
<s>
0	B-Application
A.D.	I-Application
originally	O
began	O
in	O
2001	O
as	O
a	O
comprehensive	O
total	O
conversion	O
mod	O
concept	O
for	O
Age	B-Application
of	I-Application
Empires	I-Application
II	I-Application
:	I-Application
The	I-Application
Age	I-Application
of	I-Application
Kings	I-Application
.	O
</s>
<s>
On	O
10	O
July	O
2009	O
,	O
Wildfire	O
Games	O
released	O
the	O
source	O
code	O
for	O
0	B-Application
A.D.	I-Application
under	O
the	O
GNU	O
GPLv2	O
(	O
or	O
later	O
)	O
license	O
,	O
and	O
made	O
the	O
artwork	O
available	O
under	O
the	O
CC	O
BY-SA	O
license	O
.	O
</s>
<s>
There	O
were	O
around	O
ten	O
to	O
fifteen	O
people	O
working	O
on	O
0	B-Application
A.D.	I-Application
around	O
23	O
March	O
2010	O
;	O
but	O
since	O
development	O
started	O
,	O
over	O
100	O
people	O
have	O
contributed	O
to	O
the	O
project	O
.	O
</s>
<s>
In	O
2012	O
,	O
0	B-Application
A.D.	I-Application
received	O
second	O
place	O
in	O
the	O
IndieDB	O
Player	O
's	O
Choice	O
Upcoming	O
Indie	O
Game	O
of	O
the	O
Year	O
competition	O
.	O
</s>
<s>
0	B-Application
A.D.	I-Application
has	O
been	O
generally	O
well	O
received	O
.	O
</s>
<s>
Between	O
2010	O
and	O
June	O
2021	O
,	O
the	O
game	O
was	O
downloaded	O
from	O
SourceForge.net	B-Application
over	O
1.3	O
million	O
times	O
.	O
</s>
