<s>
The	O
Spring	B-Application
Engine	I-Application
(	O
also	O
termed	O
SpringRTS	O
and	O
formerly	O
TA	B-Application
Spring	I-Application
)	O
,	O
is	O
a	O
game	O
engine	O
for	O
real-time	O
strategy	O
(	O
RTS	O
)	O
video	O
games	O
.	O
</s>
<s>
The	O
game	O
engine	O
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
,	O
subject	O
to	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>
The	O
development	O
was	O
initiated	O
by	O
Stefan	O
Johansson	O
,	O
Tomaz	O
Kunaver	O
,	O
and	O
Jelmer	O
Cnossen	O
,	O
members	O
of	O
the	O
Swedish	O
Yankspankers	O
game	O
clan	O
under	O
the	O
name	O
TA	B-Application
Spring	I-Application
.	O
</s>
<s>
The	O
project	O
aimed	O
originally	O
to	O
bring	O
the	O
gameplay	O
experience	O
of	O
Total	B-Application
Annihilation	I-Application
into	O
three	O
dimensions	O
and	O
to	O
have	O
the	O
game	O
run	O
the	O
mods	O
and	O
third-party	B-General_Concept
units	O
from	O
Total	B-Application
Annihilation	I-Application
.	O
</s>
<s>
Since	O
then	O
,	O
the	O
project	O
evolved	O
from	O
a	O
mere	O
TA	O
clone	O
to	O
a	O
general	O
RTS	O
game	O
engine	O
including	O
more	O
flexible	O
features	O
like	O
built-in	O
high-level	B-Language
extensibility	B-Architecture
through	O
a	O
Lua	B-Language
scripting	I-Language
interface	O
.	O
</s>
<s>
There	O
are	O
also	O
currently	O
a	O
number	O
of	O
single	O
player	O
missions	O
,	O
built	O
on	O
frameworks	O
utilizing	O
the	O
engine	O
's	O
Lua	B-Language
scripting	I-Language
abilities	O
.	O
</s>
<s>
There	O
are	O
also	O
a	O
large	O
number	O
of	O
skirmish	O
artificial	B-Application
intelligences	I-Application
(	O
AIs	B-Application
)	O
,	O
allowing	O
for	O
offline	O
play	O
or	O
extra	O
players	O
in	O
an	O
online	O
game	O
.	O
</s>
<s>
The	O
Spring	B-Application
Engine	I-Application
uses	O
a	O
deterministic	O
game	O
simulation	O
which	O
is	O
executed	O
simultaneously	O
on	O
all	O
game	O
clients	O
.	O
</s>
<s>
Multiplayer	O
is	O
supported	O
on	O
both	O
Linux	B-Application
and	O
Windows	B-Application
.	O
</s>
<s>
A	O
pre-game	O
lobby	O
uses	O
a	O
specially	O
designed	O
protocol	O
similar	O
to	O
that	O
of	O
Internet	B-Protocol
Relay	I-Protocol
Chat	I-Protocol
to	O
facilitate	O
chat	O
,	O
player	O
match-making	O
,	O
and	O
the	O
adjustment	O
of	O
battle	O
options	O
.	O
</s>
<s>
Most	O
popular	O
in	O
this	O
area	O
are	O
the	O
"	O
chicken	O
"	O
modes	O
of	O
Zero-K	B-Application
and	O
Balanced	O
Annihilation	O
,	O
where	O
a	O
player	O
has	O
to	O
defend	O
against	O
waves	O
of	O
monsters	O
.	O
</s>
<s>
Skirmish	O
AIs	B-Application
(	O
or	O
bots	O
)	O
are	O
needed	O
to	O
get	O
a	O
normal	O
single	O
player	O
game	O
running	O
.	O
</s>
<s>
The	O
engine	O
supports	O
Skirmish	O
AI	B-Application
plug-ins	B-Application
to	O
be	O
written	O
in	O
a	O
variety	O
of	O
programming	O
languages	O
.	O
</s>
<s>
Currently	O
these	O
are	O
Lua	B-Language
,	O
C	B-Language
,	O
C++	B-Language
,	O
Python	B-Language
and	O
the	O
JVM	B-Language
languages	I-Language
like	O
Java	B-Language
and	O
Groovy	B-Application
.	O
</s>
<s>
It	O
is	O
also	O
possible	O
to	O
develop	O
plug-ins	B-Application
to	O
support	O
more	O
languages	O
.	O
</s>
<s>
The	O
unit	O
files	O
of	O
Total	B-Application
Annihilation	I-Application
are	O
compatible	O
,	O
allowing	O
third-party	B-General_Concept
units	O
to	O
be	O
imported	O
.	O
</s>
<s>
The	O
scripting	O
language	O
allows	O
for	O
a	O
customizable	O
gameplay	O
and	O
user	B-Application
interface	I-Application
modifications	O
.	O
</s>
<s>
The	O
third-party	B-General_Concept
AI	B-Application
allows	O
for	O
varying	O
degrees	O
of	O
difficulty	O
.	O
</s>
<s>
Springs	O
source	O
code	O
,	O
licensed	O
under	O
the	O
GNU	B-License
GPL-2.0-or-later	I-License
,	O
is	O
primarily	O
written	O
in	O
the	O
programming	O
language	O
C++	O
,	O
as	O
is	O
springlobby	O
.	O
</s>
<s>
An	O
alternative	O
lobby	O
,	O
TASClient	O
,	O
is	O
written	O
in	O
Delphi	B-Language
,	O
and	O
there	O
are	O
lobby	O
servers	O
-	O
used	O
to	O
organize	O
multi-player	O
games	O
-	O
written	O
in	O
Java	B-Language
and	O
Python	B-Language
.	O
</s>
<s>
The	O
C++	B-Language
code	I-Language
structure	O
is	O
written	O
in	O
an	O
object-oriented	O
manner	O
and	O
is	O
documented	O
to	O
some	O
extent	O
using	O
Doxygen	B-Language
.	O
</s>
<s>
The	O
official	O
source	O
code	O
package	O
includes	O
project	O
files	O
for	O
various	O
integrated	B-Application
development	I-Application
environments	I-Application
(	O
IDEs	O
)	O
and	O
building	O
tools	O
,	O
including	O
CMake	B-Language
,	O
KDevelop	B-Language
,	O
Visual	B-Application
C++	I-Application
7.0/8.0	O
,	O
and	O
Xcode	B-Operating_System
.	O
</s>
<s>
Various	O
games	O
leveraging	O
the	O
Spring	B-Application
engine	I-Application
range	O
from	O
free	O
content	O
games	O
with	O
minimal	O
restrictions	O
on	O
use	O
and	O
distribution	O
to	O
games	O
with	O
commercially	O
licensed	O
art	O
,	O
such	O
as	O
P.U.R.E.	O
</s>
<s>
Additionally	O
,	O
content	O
from	O
Total	B-Application
Annihilation	I-Application
has	O
been	O
modified	O
to	O
run	O
on	O
the	O
Spring	B-Application
Engine	I-Application
,	O
although	O
playing	O
games	O
that	O
incorporate	O
such	O
content	O
requires	O
that	O
one	O
own	O
a	O
copy	O
of	O
the	O
original	O
Total	B-Application
Annihilation	I-Application
game	O
.	O
</s>
<s>
Some	O
are	O
based	O
upon	O
and	O
use	O
content	O
from	O
the	O
original	O
Total	B-Application
Annihilation	I-Application
game	O
,	O
this	O
includes	O
the	O
games	O
:	O
Balanced	O
Annihilation	O
,	O
Tech	O
Annihilation	O
,	O
NOTA	O
,	O
and	O
XTA	O
.	O
</s>
<s>
However	O
,	O
there	O
are	O
many	O
games	O
which	O
are	O
derivatives	O
of	O
other	O
works	O
of	O
fiction	O
,	O
such	O
as	O
a	O
Gundam	O
game	O
,	O
a	O
Warhammer	O
40,000	O
game	O
,	O
and	O
a	O
Star	B-Application
Wars	I-Application
game	O
based	O
on	O
the	O
Galactic	O
Civil	O
War	O
.	O
</s>
<s>
There	O
are	O
also	O
several	O
fully	O
original	O
games	O
,	O
including	O
"	O
Expand	O
&	O
Exterminate	O
"	O
,	O
a	O
strategic	O
game	O
inspired	O
by	O
Earth	B-Application
2150	I-Application
,	O
"	O
The	O
Cursed	O
"	O
,	O
a	O
unique	O
mixture	O
of	O
science	O
fiction	O
and	O
fantasy	O
,	O
and	O
"	O
Kernel	O
Panic	O
"	O
,	O
a	O
Darwinia-esque	O
game	O
emphasizing	O
simplicity	O
.	O
</s>
<s>
As	O
the	O
name	O
suggests	O
,	O
the	O
game	O
rebalanced	O
Absolute	O
Annihilation	O
,	O
which	O
was	O
a	O
rebalanced	O
version	O
of	O
the	O
Total	B-Application
Annihilation	I-Application
game	O
Uberhack	O
.	O
</s>
<s>
It	O
features	O
all	O
the	O
previous	O
units	O
from	O
retail	O
version	O
of	O
Total	B-Application
Annihilation	I-Application
,	O
plus	O
several	O
extras	O
for	O
each	O
faction	O
.	O
</s>
<s>
The	O
balance	O
does	O
not	O
reflect	O
Total	B-Application
Annihilation	I-Application
gameplay	O
as	O
much	O
as	O
an	O
augmented	O
version	O
of	O
Total	B-Application
Annihilation	I-Application
.	O
</s>
<s>
Beyond	O
All	O
Reason	O
(	O
also	O
known	O
as	O
BAR	O
)	O
is	O
a	O
fork	O
of	O
Balanced	O
Annihilation	O
and	O
also	O
based	O
on	O
the	O
Spring	B-Application
engine	I-Application
.	O
</s>
<s>
Although	O
the	O
gameplay	O
is	O
similar	O
to	O
Total	B-Application
Annihilation	I-Application
,	O
the	O
project	O
does	O
not	O
aim	O
to	O
be	O
just	O
a	O
copy	O
of	O
the	O
original	O
game	O
.	O
</s>
<s>
Zero-K	B-Application
(	O
formerly	O
known	O
as	O
Complete	O
Annihilation	O
)	O
started	O
as	O
a	O
fork	O
of	O
Balanced	O
Annihilation	O
,	O
and	O
so	O
can	O
trace	O
its	O
heritage	O
all	O
the	O
way	O
back	O
to	O
the	O
original	O
Total	B-Application
Annihilation	I-Application
.	O
</s>
<s>
Among	O
Spring	O
games	O
,	O
Zero-K	B-Application
is	O
notable	O
for	O
its	O
extensive	O
use	O
of	O
Lua	B-Language
scripting	I-Language
for	O
interface	O
and	O
gameplay	O
enhancements	O
,	O
and	O
unique	O
RTS	O
concepts	O
such	O
as	O
a	O
flat	O
technology	O
tree	O
.	O
</s>
<s>
Zero-K	B-Application
was	O
released	O
on	O
Steam	B-Application
as	O
a	O
standalone	O
game	O
on	O
27	O
April	O
2018	O
.	O
</s>
<s>
NOTA	O
(	O
Not	O
Original	O
Total	B-Application
Annihilation	I-Application
)	O
is	O
a	O
game	O
designed	O
for	O
larger	O
maps	O
with	O
to-scale	O
units	O
,	O
fuel	O
for	O
airplanes	O
and	O
accent	O
for	O
strategic	O
decisions	O
.	O
</s>
<s>
is	O
set	O
in	O
a	O
time	O
when	O
humans	O
are	O
at	O
war	O
against	O
an	O
evil	O
AI	B-Application
called	O
the	O
Overmind	O
.	O
</s>
<s>
Spring:1944	O
is	O
one	O
of	O
the	O
most-developed	O
games	O
on	O
the	O
Spring	B-Application
engine	I-Application
,	O
and	O
as	O
the	O
name	O
suggests	O
is	O
based	O
on	O
the	O
later	O
years	O
of	O
World	O
War	O
II	O
.	O
</s>
<s>
It	O
contains	O
nearly	O
300	O
unique	O
units	O
across	O
the	O
four	O
major	O
belligerent	O
factions	O
(	O
United	O
States	O
,	O
United	O
Kingdom	O
,	O
Nazi	O
Germany	O
and	O
the	O
USSR	O
)	O
,	O
with	O
all	O
content	O
being	O
produced	O
by	O
several	O
main	O
developers	O
and	O
a	O
handful	O
of	O
contributors	O
,	O
and	O
is	O
the	O
most	O
popular	O
independent	O
production	O
project	O
on	O
the	O
Spring	B-Application
engine	I-Application
.	O
</s>
<s>
Kernel	O
Panic	O
is	O
a	O
game	O
that	O
has	O
no	O
connection	O
to	O
Total	B-Application
Annihilation	I-Application
.	O
</s>
<s>
Preceding	O
all	O
other	O
active	O
games	O
,	O
XTA	O
,	O
short	O
for	O
eXtended	O
Total	B-Application
Annihilation	I-Application
was	O
the	O
original	O
Total	B-Application
Annihilation	I-Application
based	O
game	O
developed	O
on	O
the	O
Spring	B-Application
Project	I-Application
.	O
</s>
<s>
It	O
features	O
all	O
units	O
from	O
the	O
retail	O
version	O
of	O
Total	B-Application
Annihilation	I-Application
with	O
a	O
few	O
additional	O
ones	O
added	O
to	O
each	O
faction	O
.	O
</s>
<s>
Evolution	O
RTS	O
was	O
the	O
first	O
Spring-based	O
game	O
released	O
(	O
as	O
free	O
to	O
play	O
)	O
on	O
Steam	B-Application
,	O
in	O
April	O
2014	O
.	O
</s>
<s>
It	O
was	O
removed	O
from	O
Steam	B-Application
in	O
April	O
2020	O
.	O
</s>
<s>
Spring	O
was	O
reviewed	O
in	O
French	O
print	O
computer	O
magazine	O
"	O
Linux	B-Application
Pratique	O
"	O
in	O
February	O
2009	O
.	O
</s>
