<s>
Freeciv	B-Application
is	O
a	O
single	O
-	O
and	O
multiplayer	O
turn-based	O
strategy	B-Application
game	I-Application
for	O
workstations	B-Device
and	O
personal	B-Device
computers	I-Device
inspired	O
by	O
the	O
proprietary	B-Application
Sid	B-Application
Meier	I-Application
's	I-Application
Civilization	I-Application
series	O
.	O
</s>
<s>
It	O
is	O
available	O
for	O
most	O
desktop	O
computer	B-General_Concept
operating	I-General_Concept
systems	I-General_Concept
and	O
available	O
in	O
an	O
online	O
browser	B-Protocol
version	I-Protocol
.	O
</s>
<s>
Released	O
under	O
the	O
GNU	B-License
GPL-2.0-or-later	I-License
,	O
Freeciv	B-Application
is	O
free	B-Application
and	I-Application
open	I-Application
source	I-Application
software	I-Application
.	O
</s>
<s>
The	O
game	O
's	O
default	O
settings	O
are	O
closest	O
to	O
Civilization	B-Application
II	I-Application
,	O
in	O
both	O
gameplay	O
and	O
graphics	O
,	O
including	O
the	O
units	O
and	O
the	O
isometric	B-Application
grid	O
.	O
</s>
<s>
Freeciv	B-Application
is	O
playable	O
online	O
at	O
Longturn.net,	O
fciv.net,	O
freecivweb.org	O
and	O
a	O
number	O
of	O
temporary	O
private	O
servers	O
that	O
may	O
or	O
may	O
not	O
be	O
listed	O
on	O
metaserver	O
.	O
</s>
<s>
Players	O
take	O
the	O
role	O
of	O
tribal	O
leaders	O
in	O
4000	O
B.C.	O
</s>
<s>
The	O
game	O
ends	O
when	O
one	O
civilization	B-Application
has	O
eradicated	O
all	O
others	O
or	O
accomplished	O
the	O
goal	O
of	O
space	O
colonization	O
,	O
or	O
at	O
a	O
given	O
deadline	O
.	O
</s>
<s>
If	O
more	O
than	O
one	O
civilization	B-Application
remains	O
at	O
the	O
deadline	O
,	O
the	O
player	O
with	O
the	O
highest	O
score	O
wins	O
.	O
</s>
<s>
Points	O
are	O
awarded	O
for	O
the	O
size	O
of	O
a	O
civilization	B-Application
,	O
its	O
wealth	O
,	O
and	O
cultural	O
and	O
scientific	O
advances	O
.	O
</s>
<s>
At	O
the	O
computer	B-General_Concept
science	I-General_Concept
department	O
at	O
Aarhus	O
University	O
,	O
three	O
students	O
,	O
avid	O
players	O
of	O
XPilot	B-Language
and	O
of	O
Sid	O
Meier	O
’s	O
Civilization	B-Application
,	O
which	O
was	O
a	O
stand-alone	O
PC	O
game	O
for	O
MS-DOS	B-Application
,	O
decided	O
to	O
find	O
out	O
whether	O
the	O
two	O
could	O
be	O
fused	O
into	O
an	O
X-based	B-Operating_System
multiplayer	O
Civilization-like	O
strategy	B-Application
game	I-Application
.	O
</s>
<s>
The	O
rules	O
of	O
the	O
game	O
were	O
close	O
to	O
Civilization	B-Application
,	O
while	O
the	O
client/server	B-Operating_System
architecture	I-Operating_System
was	O
basically	O
that	O
of	O
XPilot	B-Language
.	O
</s>
<s>
For	O
the	O
developers	O
,	O
Freeciv	B-Application
1.0	O
was	O
a	O
successful	O
proof	O
of	O
concept	O
,	O
but	O
a	O
rather	O
boring	O
game	O
,	O
so	O
they	O
went	O
back	O
to	O
XPilot	B-Language
.	O
</s>
<s>
Other	O
players	O
and	O
developers	O
took	O
over	O
;	O
they	O
made	O
the	O
game	O
available	O
on	O
many	O
other	O
operating	B-General_Concept
systems	I-General_Concept
,	O
including	O
Linux	B-Application
,	O
Solaris	B-Application
,	O
Ultrix	B-Operating_System
,	O
Amiga	B-Application
OS	I-Application
,	O
and	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Linux	B-Application
distributions	I-Application
started	O
to	O
include	O
Freeciv	B-Application
.	O
</s>
<s>
The	O
main	O
development	O
goal	O
remained	O
to	O
make	O
a	O
Civilization-like	O
game	O
playable	O
over	O
the	O
Internet	O
,	O
with	O
participants	O
on	O
different	O
continents	O
,	O
even	O
when	O
connected	O
with	O
14400	O
bit/s	O
modems	B-Application
.	O
</s>
<s>
Freeciv	B-Application
achieved	O
this	O
by	O
using	O
an	O
asynchronous	B-Operating_System
client-server	B-Operating_System
protocol	I-Operating_System
:	O
during	O
each	O
turn	O
,	O
human	O
users	O
play	O
concurrently	O
,	O
and	O
their	O
actions	O
are	O
sent	O
to	O
the	O
server	B-Application
for	O
processing	O
without	O
awaiting	O
the	O
results	O
.	O
</s>
<s>
This	O
kept	O
the	O
game	O
playable	O
with	O
network	B-Protocol
latency	I-Protocol
up	O
to	O
a	O
few	O
hundreds	O
of	O
milliseconds	O
.	O
</s>
<s>
Computer	O
players	O
are	O
implemented	O
directly	O
in	O
the	O
server	B-Application
;	O
they	O
do	O
not	O
play	O
concurrently	O
with	O
human	O
players	O
,	O
but	O
separately	O
,	O
in	O
between	O
turns	O
.	O
</s>
<s>
A	O
public	O
server	B-Application
was	O
installed	O
on	O
which	O
games	O
could	O
be	O
played	O
around	O
the	O
clock	O
;	O
it	O
retained	O
the	O
games	O
and	O
published	O
a	O
post-game	O
analysis	O
webpage	O
with	O
per-player	O
statistics	O
and	O
an	O
animated	O
map	O
replay	O
.	O
</s>
<s>
Subsequent	O
1.x	O
releases	O
improved	O
the	O
GUI	O
,	O
improved	O
the	O
gameplay	O
,	O
optimized	O
playability	O
over	O
poor	O
connections	O
,	O
and	O
added	O
many	O
small	O
features	O
.	O
</s>
<s>
In	O
practice	O
,	O
from	O
around	O
2002	O
,	O
experienced	O
players	O
would	O
form	O
teams	O
at	O
the	O
start	O
of	O
the	O
game	O
;	O
a	O
fork	B-Application
of	O
Freeciv	B-Application
included	O
specific	O
features	O
for	O
team	O
play	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
multiplayer	O
games	O
were	O
almost	O
always	O
played	O
in	O
teams	O
and	O
typically	O
took	O
longer	O
to	O
finish	O
when	O
compared	O
to	O
1.x	O
games	O
.	O
</s>
<s>
In	O
2006	O
,	O
TCP	B-Protocol
and	O
UDP	B-Protocol
port	O
number	O
5556	O
was	O
assigned	O
to	O
Freeciv	B-Application
by	O
IANA	O
.	O
</s>
<s>
In	O
2017	O
,	O
after	O
being	O
hosted	O
on	O
Gna	B-Protocol
!	I-Protocol
</s>
<s>
for	O
15	O
years	O
,	O
Freeciv	B-Application
moved	O
its	O
source	B-General_Concept
repository	I-General_Concept
to	O
GitHub	B-Application
.	O
</s>
<s>
In	O
2000	O
CNN	B-Architecture
placed	O
Freeciv	B-Application
among	O
the	O
"	O
Top	O
10	O
Linux	B-Application
games	O
for	O
the	O
holidays	O
"	O
.	O
</s>
<s>
In	O
2005	O
,	O
in	O
an	O
O'Reilly	O
article	O
on	O
"	O
Open	O
Source	O
Mac	O
Gaming	O
"	O
,	O
Freeciv	B-Application
was	O
recommended	O
.	O
</s>
<s>
In	O
2008	O
APC	O
named	O
Freeciv	B-Application
among	O
the	O
"	O
Top	O
5	O
best	O
(	O
free	O
)	O
open	O
source	O
games	O
"	O
.	O
</s>
<s>
Linux	B-Application
Format	O
selected	O
it	O
as	O
"	O
HotPick	O
"	O
in	O
April	O
2010	O
and	O
in	O
October	O
2014	O
.	O
</s>
<s>
Freeciv	B-Application
was	O
described	O
as	O
an	O
example	O
in	O
The	O
Art	O
of	O
Unix	O
Programming	O
by	O
Eric	O
S	O
.	O
Raymond	O
.	O
</s>
<s>
Studies	O
and	O
courses	O
have	O
used	O
Freeciv	B-Application
as	O
a	O
platform	O
for	O
experimenting	O
with	O
the	O
design	O
and	O
programming	O
of	O
intelligent	B-General_Concept
agents	I-General_Concept
.	O
</s>
<s>
In	O
2016	O
Freeciv	B-Application
was	O
used	O
as	O
a	O
challenge	O
after	O
chess	B-Application
and	O
Go	O
for	O
a	O
commercial	O
AI	B-Application
.	O
</s>
<s>
Freeciv	B-Application
is	O
very	O
configurable	O
,	O
down	O
to	O
the	O
specific	O
rules	O
,	O
so	O
it	O
can	O
be	O
played	O
in	O
Freeciv	B-Application
(	O
default	O
)	O
mode	O
,	O
Civilization	B-Application
mode	O
,	O
Civilization	B-Application
II	I-Application
mode	O
,	O
or	O
a	O
custom	O
mode	O
.	O
</s>
<s>
The	O
maximum	O
number	O
of	O
players	O
is	O
126	O
in	O
the	O
latest	O
version	O
of	O
Freeciv	B-Application
.	O
</s>
<s>
In	O
order	O
to	O
play	O
a	O
game	O
of	O
Freeciv	B-Application
,	O
a	O
user	O
must	O
start	O
up	O
a	O
Freeciv	B-Application
client	B-Protocol
and	O
connect	O
it	O
to	O
a	O
Freeciv	B-Application
server	B-Application
.	O
</s>
<s>
Initially	O
,	O
the	O
server	B-Application
is	O
in	O
pre-game	O
phase	O
;	O
in	O
this	O
phase	O
,	O
clients	O
can	O
connect	O
and	O
game	O
configuration	O
parameters	O
can	O
be	O
changed	O
.	O
</s>
<s>
At	O
some	O
point	O
,	O
the	O
server	B-Application
may	O
be	O
ordered	O
to	O
start	O
a	O
game	O
;	O
in	O
response	O
,	O
it	O
creates	O
game	O
players	O
(	O
nations	O
)	O
and	O
the	O
game	O
map	O
,	O
and	O
assigns	O
every	O
player	O
to	O
either	O
a	O
Freeciv	B-Application
client	B-Protocol
or	O
a	O
computer	O
player	O
,	O
as	O
specified	O
by	O
the	O
configuration	O
.	O
</s>
<s>
From	O
that	O
point	O
on	O
,	O
the	O
game	O
will	O
run	O
until	O
it	O
ends	O
or	O
is	O
terminated	O
;	O
the	O
server	B-Application
can	O
never	O
get	O
back	O
into	O
pre-game	O
state	O
.	O
</s>
<s>
The	O
user	O
can	O
also	O
start	O
a	O
game	O
directly	O
from	O
the	O
client	B-Protocol
:	O
this	O
automatically	O
starts	O
a	O
Freeciv	B-Application
server	B-Application
,	O
connects	O
to	O
it	O
and	O
starts	O
the	O
game	O
.	O
</s>
<s>
Freeciv	B-Application
's	O
graphics	O
system	O
is	O
configurable	O
:	O
originally	O
,	O
map	O
display	O
was	O
always	O
in	O
overhead	O
mode	O
(	O
like	O
in	O
Civ	B-Application
I	I-Application
)	O
.	O
</s>
<s>
Isometric	B-Application
mode	O
(	O
like	O
in	O
Civ	B-Application
II	I-Application
and	O
III	B-Application
)	O
and	O
optionally	O
hexagonal	O
tiling	O
(	O
like	O
in	O
Civ	B-Application
V	I-Application
and	O
VI	B-Application
)	O
were	O
added	O
later	O
.	O
</s>
<s>
In	O
both	O
modes	O
,	O
look	O
can	O
be	O
further	O
customized	O
by	O
switching	O
to	O
an	O
alternative	O
set	O
of	O
graphics	O
(	O
called	O
a	O
tileset	B-Application
)	O
.	O
</s>
<s>
Freeciv	B-Application
supports	O
human-to-human	O
multiplayer	O
gameplay	O
and	O
artificial	B-Application
intelligence	I-Application
(	O
AI	B-Application
)	O
computer	O
players	O
.	O
</s>
<s>
The	O
AI	B-Application
players	O
move	O
separately	O
,	O
partly	O
at	O
the	O
start	O
of	O
a	O
turn	O
,	O
partly	O
at	O
the	O
end	O
.	O
</s>
<s>
In	O
releases	O
before	O
2.0	O
,	O
AI	B-Application
players	O
could	O
not	O
engage	O
in	O
diplomatic	O
relationships	O
with	O
human	O
players	O
.	O
</s>
<s>
Under	O
the	O
current	O
releases	O
,	O
AI	B-Application
players	O
will	O
engage	O
in	O
a	O
very	O
predictable	O
,	O
rules-based	O
diplomacy	O
.	O
</s>
<s>
Basic	O
scripting	O
is	O
available	O
with	O
Freeciv	B-Application
,	O
but	O
is	O
not	O
available	O
in	O
Civworld	O
.	O
</s>
<s>
There	O
are	O
different	O
clients	O
available	O
SDL	B-Operating_System
,	O
GTK+	B-Application
(	O
version3	O
)	O
and	O
Xaw3D	B-Library
A	O
Qt	B-Language
client	B-Protocol
was	O
added	O
in	O
version	O
2.5	O
.	O
</s>
<s>
The	O
Freeciv	B-Application
interface	O
is	O
available	O
in	O
over	O
30	O
different	O
languages	O
.	O
</s>
<s>
Originally	O
developed	O
on	O
IRIX	B-Operating_System
,	O
Freeciv	B-Application
has	O
been	O
ported	O
to	O
many	O
different	O
operating	B-General_Concept
systems	I-General_Concept
:	O
it	O
is	O
distributed	O
with	O
many	O
Linux	B-Application
distributions	I-Application
,	O
offers	O
installers	O
for	O
Microsoft	B-Application
Windows	I-Application
,	O
and	O
has	O
been	O
known	O
to	O
run	O
on	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
MorphOS	B-Operating_System
,	O
Solaris	B-Application
,	O
Ultrix	B-Operating_System
,	O
QNX	B-Operating_System
,	O
OS/2	B-Application
,	O
Cygwin	B-Language
,	O
AmigaOS	B-Application
,	O
AROS	B-Application
,	O
RISC	B-Operating_System
OS	I-Operating_System
,	O
Maemo	B-Operating_System
,	O
ZETA	B-Device
,	O
SkyOS	B-Application
,	O
various	O
BSDs	B-Operating_System
,	O
and	O
smartphones	O
and	O
tablets	O
running	O
Android	B-Application
.	O
</s>
<s>
As	O
of	O
version	O
2.4	O
,	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
and	O
as	O
of	O
version	O
2.3	O
,	O
Windows	O
versions	O
older	O
than	O
Windows	B-Application
XP	I-Application
SP3	O
are	O
no	O
longer	O
supported	O
.	O
</s>
<s>
Freeciv	B-Application
is	O
available	O
in	O
the	O
PortableApps	B-Application
format	O
.	O
</s>
<s>
Freeciv21	O
is	O
a	O
fork	B-Application
of	O
the	O
original	O
Freeciv	B-Application
project	O
started	O
with	O
the	O
intention	O
of	O
modernising	O
the	O
code	O
and	O
the	O
client	B-Protocol
interface	O
,	O
and	O
also	O
adjusting	O
the	O
software	O
more	O
to	O
the	O
needs	O
of	O
multiplayer	O
longturn	O
variant	O
.	O
</s>
<s>
FCIV.NET	O
is	O
a	O
variant	O
of	O
Freeciv	B-Application
which	O
focuses	O
on	O
3D	O
graphics	O
and	O
is	O
playable	O
for	O
free	O
on	O
www.fciv.net	O
.	O
</s>
<s>
Freeciv-web	O
is	O
a	O
version	O
of	O
Freeciv	B-Application
playable	O
online	O
in	O
any	O
modern	O
web	B-Application
browser	I-Application
.	O
</s>
<s>
It	O
supports	O
2D	O
isometric	B-Application
graphics	I-Application
or	O
3D	O
graphics	O
using	O
WebGL	B-Library
.	O
</s>
<s>
The	O
game	O
is	O
a	O
fork	B-Application
of	O
the	O
Freeciv	B-Application
project	O
,	O
with	O
the	O
goal	O
of	O
redesigning	O
the	O
desktop	O
game	O
into	O
a	O
version	O
which	O
can	O
be	O
played	O
online	O
.	O
</s>
<s>
Freeciv-web	O
introduced	O
several	O
new	O
features	O
,	O
such	O
as	O
play-by-email	O
support	O
freely	O
available	O
to	O
anyone	O
online	O
,	O
and	O
support	O
for	O
playing	O
the	O
game	O
on	O
any	O
real-world	O
map	O
location	O
by	O
choosing	O
a	O
map	O
using	O
Mapbox	O
,	O
which	O
is	O
not	O
available	O
in	O
commercial	O
games	O
in	O
the	O
genre	O
.	O
</s>
<s>
The	O
game	O
's	O
default	O
settings	O
are	O
closest	O
to	O
Civilization	B-Application
II	I-Application
,	O
both	O
in	O
gameplay	O
and	O
graphics	O
(	O
including	O
the	O
units	O
and	O
the	O
isometric	B-Application
grid	O
)	O
.	O
</s>
<s>
The	O
proposal	O
to	O
create	O
a	O
web-version	O
of	O
Freeciv	B-Application
was	O
made	O
6	O
April	O
2007	O
on	O
the	O
Freeciv	B-Application
mailing	O
lists	O
,	O
and	O
documented	O
on	O
the	O
Freeciv.org	O
wiki	O
.	O
</s>
<s>
Freeciv-web	O
was	O
originally	O
created	O
by	O
Andreas	O
Røsdal	O
,	O
but	O
is	O
now	O
maintained	O
by	O
several	O
Freeciv	B-Application
developers	O
on	O
GitHub	B-Application
.	O
</s>
<s>
Freeciv-web	O
is	O
free	B-Application
and	I-Application
open	I-Application
source	I-Application
software	I-Application
.	O
</s>
<s>
The	O
Freeciv	B-Application
C	B-Language
server	B-Application
is	O
released	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
,	O
while	O
the	O
Freeciv-web	O
client	O
is	O
released	O
under	O
the	O
GNU	B-Application
Affero	I-Application
General	I-Application
Public	I-Application
License	I-Application
.	O
</s>
<s>
Freeciv-web	O
supports	O
human-to-human	O
multiplayer	O
gameplay	O
and	O
artificial	B-Application
intelligence	I-Application
(	O
AI	B-Application
)	O
computer	O
players	O
.	O
</s>
<s>
Its	O
features	O
are	O
similar	O
to	O
the	O
Freeciv	B-Application
C	B-Language
client	B-Protocol
,	O
although	O
not	O
all	O
of	O
the	O
user-interface	O
has	O
been	O
ported	O
from	O
the	O
C	B-Language
client	B-Protocol
yet	O
.	O
</s>
<s>
The	O
Freeciv-web	O
server	B-Application
on	O
play.freeciv.org	O
was	O
shut	O
down	O
in	O
March	O
2018	O
,	O
but	O
the	O
project	O
was	O
revived	O
by	O
a	O
group	O
of	O
volunteers	O
on	O
freecivweb.org	O
.	O
</s>
<s>
Freeciv-web	O
can	O
be	O
played	O
online	O
at	O
a	O
number	O
of	O
servers	O
such	O
as	O
freecivweb.org	O
.	O
</s>
<s>
All	O
the	O
features	O
required	O
to	O
play	O
a	O
full	O
game	O
of	O
Freeciv	B-Application
are	O
in	O
place	O
.	O
</s>
<s>
Freeciv	B-Application
Longturn	O
is	O
a	O
specialized	O
large-group-multiplayer-online-strategy	O
variant	O
of	O
Freeciv	B-Application
featuring	O
daylong	O
game	O
turns	O
with	O
large	O
amounts	O
of	O
human	O
opponents	O
per	O
map	O
,	O
allowing	O
for	O
optimal	O
timing	O
to	O
build	O
up	O
strategic	O
plans	O
and	O
readapt	O
them	O
to	O
the	O
circumstances	O
of	O
each	O
turn	O
.	O
</s>
<s>
Longturn	O
's	O
first	O
game	O
,	O
now	O
called	O
LT0	O
,	O
started	O
around	O
2004	O
on	O
the	O
Polish	O
Civilization	B-Application
fanpage	O
civ.org.pl	O
and	O
is	O
now	O
conducted	O
at	O
Longturn.net	O
.	O
</s>
<s>
and	O
,	O
recently	O
,	O
Longturn	O
Discord	O
server	B-Application
where	O
the	O
community	O
is	O
currently	O
centered	O
.	O
</s>
<s>
There	O
is	O
ongoing	O
development	O
of	O
a	O
few	O
non-standard	O
rulesets	O
specifically	O
adjusted	O
for	O
longturn	O
multiplayer	O
games	O
,	O
diverging	O
from	O
the	O
rules	O
of	O
the	O
original	O
Civilization	B-Application
which	O
was	O
created	O
as	O
a	O
single-player	O
game	O
.	O
</s>
<s>
Greatturn	O
was	O
a	O
similar	O
concept	O
on	O
another	O
server	B-Application
.	O
</s>
<s>
Power	O
of	O
Planets	O
-	O
Earth	O
(	O
formerly	O
known	O
as	O
GaCivs	O
)	O
is	O
a	O
free-to-play	O
MMO-RTS	O
variant	O
based	O
on	O
FreeCiv	B-Application
.	O
</s>
