<s>
Emscripten	B-Language
is	O
an	O
LLVM/Clang	O
-based	O
compiler	B-Language
that	O
compiles	B-Language
C	B-Language
and	O
C++	B-Language
source	O
code	O
to	O
WebAssembly	B-Language
(	O
or	O
to	O
a	O
subset	O
of	O
JavaScript	B-Language
known	O
as	O
asm.js	B-Language
,	O
its	O
original	O
compilation	B-Language
target	O
before	O
the	O
advent	O
of	O
WebAssembly	B-Language
in	O
2017	O
)	O
,	O
primarily	O
for	O
execution	O
in	O
web	B-Application
browsers	I-Application
.	O
</s>
<s>
Emscripten	B-Language
allows	O
applications	O
and	O
libraries	O
written	O
in	O
C	B-Language
or	O
C++	B-Language
to	O
be	O
compiled	B-Language
ahead	O
of	O
time	O
and	O
run	O
efficiently	O
in	O
web	B-Application
browsers	I-Application
,	O
typically	O
at	O
speeds	O
comparable	O
to	O
or	O
faster	O
than	O
interpreted	B-Application
or	O
dynamically	O
compiled	B-Language
JavaScript	B-Language
.	O
</s>
<s>
It	O
even	O
emulates	O
an	O
entire	O
POSIX	O
operating	O
system	O
,	O
enabling	O
programmers	O
to	O
use	O
functions	O
from	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
(	O
libc	B-Language
)	O
.	O
</s>
<s>
With	O
the	O
more	O
recent	O
development	O
of	O
the	O
WebAssembly	B-Language
System	O
Interface	O
(	O
WASI	O
)	O
and	O
WebAssembly	B-Language
runtimes	B-Device
such	O
as	O
Node.js	B-Language
,	O
Wasmtime	O
,	O
and	O
Wasmer	O
,	O
Emscripten	B-Language
can	O
also	O
be	O
used	O
to	O
compile	B-Language
to	O
WebAssembly	B-Language
for	O
execution	O
in	O
non-Web	O
embeddings	O
as	O
well	O
.	O
</s>
<s>
Emscripten	B-Language
has	O
been	O
used	O
to	O
port	O
a	O
number	O
of	O
C/C	O
++	O
code	O
bases	O
to	O
WebAssembly	B-Language
,	O
including	O
Unreal	B-Operating_System
Engine	I-Operating_System
3	O
,	O
SQLite	B-Language
,	O
MeshLab	B-Language
,	O
Bullet	B-Application
physics	I-Application
.	O
</s>
<s>
AutoCAD	B-Algorithm
,	O
and	O
a	O
subset	O
of	O
the	O
Qt	B-Language
application	I-Language
framework	I-Language
.	O
</s>
<s>
Other	O
examples	O
of	O
software	O
ported	O
to	O
WebAssembly	B-Language
via	O
Emscripten	B-Language
include	O
the	O
following	O
:	O
</s>
<s>
The	O
Unity	B-Application
,	O
Godot	B-Application
,	O
and	O
Unreal	B-Operating_System
game	O
engines	O
provide	O
an	O
export	O
option	O
to	O
HTML5	O
,	O
utilizing	O
Emscripten	B-Language
.	O
</s>
<s>
openFrameworks	B-Application
exports	O
native	O
C++	B-Language
applications	O
to	O
HTML5	O
via	O
Emscripten	B-Language
.	O
</s>
<s>
emscripten-qt	O
permits	O
compiling	B-Language
applications	O
written	O
using	O
the	O
Qt	B-Language
application	I-Language
framework	I-Language
to	O
WebAssembly	B-Language
.	O
</s>
<s>
In	O
December	O
2014	O
,	O
the	O
Internet	O
Archive	O
launched	O
a	O
DOSBox	B-Application
emulator	O
compiled	B-Language
in	O
Emscripten	B-Language
to	O
provide	O
browser-based	O
access	O
to	O
thousands	O
of	O
archived	O
MS-DOS	B-Application
and	O
PC	O
programs	O
.	O
</s>
