<s>
Allegro	B-Language
is	O
a	O
software	B-Library
library	I-Library
for	O
video	O
game	O
development	O
.	O
</s>
<s>
The	O
functionality	O
of	O
the	O
library	O
includes	O
support	O
for	O
basic	O
2D	O
graphics	O
,	O
image	O
manipulation	O
,	O
text	O
output	O
,	O
audio	O
output	O
,	O
MIDI	O
music	O
,	O
input	O
and	O
timers	O
,	O
as	O
well	O
as	O
additional	O
routines	O
for	O
fixed-point	O
and	O
floating-point	O
matrix	B-Architecture
arithmetic	O
,	O
Unicode	O
strings	O
,	O
file	O
system	O
access	O
,	O
file	O
manipulation	O
,	O
data	O
files	O
,	O
and	O
3D	O
graphics	O
.	O
</s>
<s>
The	O
library	O
is	O
written	O
in	O
the	O
C	B-Language
programming	I-Language
language	I-Language
and	O
designed	O
to	O
be	O
used	O
with	O
C	B-Language
,	O
C++	B-Language
,	O
or	O
Objective-C	B-Language
,	O
with	O
bindings	B-Application
available	O
for	O
Python	B-Language
,	O
Lua	B-Language
,	O
Scheme	B-Language
,	O
D	B-Application
,	O
Go	B-Application
,	O
and	O
other	O
languages	O
.	O
</s>
<s>
Allegro	B-Language
comes	O
with	O
extensive	O
documentation	O
and	O
many	O
examples	O
.	O
</s>
<s>
Allegro	B-Language
supports	O
Windows	B-Application
,	O
macOS	B-Application
,	O
Unix-like	B-Operating_System
systems	I-Operating_System
,	O
Android	B-Application
,	O
and	O
iOS	B-Application
,	O
abstracting	O
their	O
application	B-Application
programming	I-Application
interfaces	I-Application
(	O
APIs	B-Application
)	O
into	O
one	O
portable	O
interface	O
.	O
</s>
<s>
It	O
can	O
run	O
also	O
on	O
top	O
of	O
Simple	B-Operating_System
DirectMedia	I-Operating_System
Layer	I-Operating_System
which	O
is	O
used	O
to	O
run	O
Allegro	B-Language
programs	O
in	O
web	O
browser	O
using	O
Emscripten	B-Language
.	O
</s>
<s>
Released	O
under	O
the	O
terms	O
of	O
the	O
zlib	B-License
license	I-License
,	O
Allegro	B-Language
is	O
free	B-Application
and	I-Application
open	I-Application
source	I-Application
software	I-Application
.	O
</s>
<s>
Initially	O
standing	O
for	O
Atari	O
Low-Level	O
Game	O
Routines	O
,	O
Allegro	B-Language
was	O
originally	O
created	O
by	O
for	O
the	O
Atari	B-Device
ST	I-Device
in	O
the	O
early	O
1990s	O
.	O
</s>
<s>
However	O
,	O
Hargreaves	O
abandoned	O
the	O
Atari	O
version	O
as	O
he	O
realized	O
the	O
platform	O
was	O
dying	O
,	O
and	O
reimplemented	O
his	O
work	O
for	O
the	O
Borland	O
C++	B-Language
and	O
DJGPP	B-Application
compilers	O
in	O
1995	O
.	O
</s>
<s>
Support	O
for	O
Borland	O
C++	B-Language
was	O
dropped	O
in	O
version	O
2.0	O
,	O
and	O
DJGPP	B-Application
was	O
the	O
only	O
supported	O
compiler	O
.	O
</s>
<s>
As	O
DJGPP	B-Application
was	O
a	O
DOS	B-Device
compiler	O
,	O
all	O
games	O
which	O
used	O
Allegro	B-Language
therefore	O
used	O
DOS	B-Device
.	O
</s>
<s>
Around	O
1998	O
,	O
Allegro	B-Language
branched	O
out	O
into	O
several	O
versions	O
.	O
</s>
<s>
A	O
port	O
to	O
Windows	B-Application
,	O
WinAllegro	B-Language
,	O
was	O
created	O
,	O
and	O
also	O
during	O
this	O
time	O
,	O
a	O
Unix	O
port	O
of	O
Allegro	B-Language
,	O
XwinAllegro	B-Language
,	O
was	O
created	O
.	O
</s>
<s>
These	O
various	O
ports	O
were	O
brought	O
together	O
during	O
the	O
Allegro	B-Language
3.9	I-Language
WIP	O
versions	O
,	O
with	O
Allegro	B-Language
4.0	I-Language
being	O
the	O
first	O
stable	O
version	O
of	O
Allegro	B-Language
to	O
support	O
multiple	O
platforms	O
.	O
</s>
<s>
Current	O
development	O
is	O
focused	O
on	O
the	O
Allegro	B-Language
5	O
branch	O
,	O
a	O
complete	O
redesign	O
of	O
both	O
the	O
API	B-Application
and	O
much	O
of	O
the	O
library	O
's	O
internal	O
operation	O
.	O
</s>
<s>
Effort	O
was	O
made	O
to	O
make	O
the	O
API	B-Application
more	O
consistent	O
and	O
multi-thread	O
safe	O
.	O
</s>
<s>
By	O
default	O
,	O
the	O
library	O
is	O
now	O
hardware	O
accelerated	O
using	O
OpenGL	B-Application
or	O
DirectX	B-Application
rendering	O
backends	O
where	O
appropriate	O
.	O
</s>
<s>
Many	O
of	O
the	O
addons	O
that	O
existed	O
as	O
separate	O
projects	O
for	O
Allegro	B-Language
4	O
now	O
interface	O
seamlessly	O
with	O
Allegro	B-Language
proper	O
and	O
are	O
bundled	O
with	O
the	O
default	O
installation	O
.	O
</s>
<s>
Allegro	B-Language
5	O
is	O
event	B-Application
driven	I-Application
.	O
</s>
<s>
Allegro	B-Language
5	O
supports	O
following	O
features	O
in	O
its	O
Core	O
API	B-Application
:	O
</s>
<s>
The	O
community	O
of	O
Allegro	B-Language
users	O
have	O
contributed	O
several	O
library	O
extensions	O
to	O
handle	O
things	O
like	O
scrolling	O
tile	O
maps	O
and	O
import	O
and	O
export	O
of	O
various	O
file	O
formats	O
.	O
</s>
<s>
Also	O
some	O
parts	O
of	O
what	O
used	O
to	O
be	O
part	O
of	O
Allegro	B-Language
,	O
is	O
now	O
separated	O
as	O
an	O
addon	O
in	O
Allegro	B-Language
5	O
.	O
</s>
