<s>
FASM	B-Application
(	O
flat	B-Application
assembler	I-Application
)	O
is	O
an	O
assembler	B-Language
for	O
x86	B-Operating_System
processors	O
.	O
</s>
<s>
It	O
supports	O
Intel-style	B-Language
assembly	B-Language
language	I-Language
on	O
the	O
IA-32	B-Device
and	O
x86-64	B-Device
computer	O
architectures	O
.	O
</s>
<s>
It	O
claims	O
high	O
speed	O
,	O
size	O
optimizations	O
,	O
operating	B-General_Concept
system	I-General_Concept
(	O
OS	O
)	O
portability	O
,	O
and	O
macro	O
abilities	O
.	O
</s>
<s>
It	O
is	O
a	O
low-level	B-Language
assembler	B-Language
and	O
intentionally	O
uses	O
very	O
few	O
command-line	B-Application
options	O
.	O
</s>
<s>
It	O
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
.	O
</s>
<s>
All	O
versions	O
of	O
FASM	B-Application
can	O
directly	O
output	O
any	O
of	O
the	O
following	O
:	O
flat	O
"	O
raw	O
"	O
binary	O
(	O
usable	O
also	O
as	O
MS-DOS	B-Application
COM	O
executable	O
or	O
SYS	O
driver	O
)	O
,	O
objects	O
:	O
Executable	O
and	O
Linkable	O
Format	O
(	O
ELF	O
)	O
or	O
Common	O
Object	O
File	O
Format	O
(	O
COFF	O
)	O
(	O
classic	O
or	O
MS-specific	O
)	O
,	O
or	O
executables	O
in	O
either	O
MZ	O
,	O
ELF	O
,	O
or	O
Portable	O
Executable	O
(	O
PE	O
)	O
format	O
(	O
including	O
WDM	O
drivers	O
,	O
allows	O
custom	O
MZ	O
DOS	O
stub	O
)	O
.	O
</s>
<s>
An	O
unofficial	O
port	O
targeting	O
the	O
ARM	B-Architecture
architecture	I-Architecture
(	O
)	O
also	O
exists	O
.	O
</s>
<s>
FASM	B-Application
is	O
completely	O
written	O
in	O
assembly	B-Language
language	I-Language
and	O
comes	O
with	O
full	O
source	O
.	O
</s>
<s>
FASM	B-Application
originally	O
ran	O
in	O
16-bit	O
flat	B-Device
real	I-Device
mode	I-Device
.	O
</s>
<s>
Designed	O
to	O
be	O
easy	O
to	O
port	O
to	O
any	O
operating	B-General_Concept
system	I-General_Concept
with	O
flat	O
32-bit	O
addressing	O
,	O
it	O
was	O
ported	O
to	O
Windows	B-Application
,	O
then	O
Linux	B-Application
.	O
</s>
<s>
FASM	B-Application
does	O
not	O
support	O
as	O
many	O
high-level	B-Application
statements	O
as	O
MASM	B-Application
or	O
TASM	B-Application
.	O
</s>
<s>
Its	O
memory-addressing	O
syntax	O
is	O
similar	O
to	O
TASM	B-Application
's	O
ideal	O
mode	O
and	O
NASM	B-Application
.	O
</s>
<s>
Brackets	O
are	O
used	O
to	O
denote	O
memory	O
operands	O
as	O
in	O
both	O
assemblers	B-Language
,	O
but	O
their	O
size	O
is	O
placed	O
outside	O
the	O
brackets	O
,	O
like	O
in	O
NASM	B-Application
.	O
</s>
<s>
FASM	B-Application
is	O
a	O
multi-pass	O
assembler	B-Language
.	O
</s>
<s>
An	O
unusual	O
FASM	B-Application
construct	O
is	O
defining	O
procedures	O
only	O
if	O
they	O
are	O
used	O
somewhere	O
in	O
the	O
code	O
,	O
something	O
that	O
in	O
most	O
languages	O
is	O
done	O
per-object	O
by	O
the	O
linker	B-Application
.	O
</s>
<s>
FASM	B-Application
is	O
based	O
on	O
the	O
"	O
same	O
source	O
,	O
same	O
output	O
"	O
principle	O
:	O
the	O
contents	O
of	O
the	O
resulting	O
file	O
are	O
not	O
affected	O
by	O
the	O
command	B-Application
line	I-Application
.	O
</s>
<s>
Such	O
an	O
approach	O
saves	O
FASM	B-Application
sources	O
from	O
compiling	O
problems	O
often	O
present	O
in	O
many	O
assembly	O
projects	O
.	O
</s>
<s>
However	O
,	O
there	O
exists	O
a	O
Win32	O
wrapper	B-Library
called	O
FA	O
,	O
which	O
mitigates	O
this	O
problem	O
.	O
</s>
<s>
FASM	B-Application
projects	O
can	O
be	O
built	O
from	O
one	O
source	O
file	O
directly	O
into	O
an	O
executable	O
file	O
without	O
a	O
linking	B-Application
stage	O
.	O
</s>
<s>
Fresh	O
,	O
an	O
internet	O
community	O
supported	O
project	O
started	O
by	O
John	O
Found	O
,	O
is	O
an	O
integrated	B-Application
development	I-Application
environment	I-Application
for	O
FASM	B-Application
.	O
</s>
<s>
Fresh	O
currently	O
supports	O
Microsoft	B-Application
Windows	I-Application
and	O
Linux	B-Application
.	O
</s>
<s>
Operating	B-General_Concept
systems	I-General_Concept
written	O
with	O
FASM	B-Application
:	O
</s>
<s>
Compilers	O
that	O
use	O
FASM	B-Application
as	O
a	O
backend	O
:	O
</s>
