<s>
Action	B-Language
Code	I-Language
Script	I-Language
(	O
ACS	O
)	O
is	O
a	O
scripting	B-Language
language	I-Language
used	O
in	O
video	O
games	O
such	O
as	O
HeXen	B-Application
and	O
some	O
modern	O
Doom	O
source	O
ports	O
,	O
such	O
as	O
ZDoom	O
.	O
</s>
<s>
It	O
is	O
syntactically	B-Application
similar	O
to	O
C	B-Language
,	O
but	O
less	O
flexible	O
.	O
</s>
<s>
Similar	O
to	O
traditional	O
code	O
,	O
ACS	O
is	O
compiled	O
using	O
ACC	O
(	O
an	O
homage	O
to	O
C	B-Language
's	O
gcc	O
utility	O
)	O
for	O
use	O
in	O
Doom	O
,	O
Hexen	B-Application
,	O
etc	O
...	O
</s>
<s>
As	O
the	O
entire	O
scripting	B-Language
language	I-Language
is	O
built	O
as	O
a	O
hack	O
on	O
top	O
of	O
the	O
Doom	O
id	B-Application
Tech	I-Application
's	O
engine	O
,	O
there	O
is	O
no	O
formal	O
support	O
for	O
any	O
object-oriented	B-Language
programming	I-Language
principles	O
.	O
</s>
<s>
The	O
syntax	B-Application
is	O
as	O
follows	O
:	O
</s>
