<s>
The	O
following	O
Comparison	B-Language
of	I-Language
Prolog	I-Language
implementations	I-Language
provides	O
a	O
reference	O
for	O
the	O
relative	O
feature	O
sets	O
and	O
performance	O
of	O
different	O
implementations	B-Application
of	O
the	O
Prolog	B-Language
computer	O
programming	O
language	O
.	O
</s>
<s>
There	O
are	O
Prolog	B-Language
implementations	B-Application
that	O
are	O
radically	O
different	O
,	O
with	O
different	O
syntax	O
and	O
different	O
semantics	O
(	O
e.g.	O
</s>
<s>
Visual	B-Application
Prolog	I-Application
)	O
and	O
sub-communities	O
have	O
developed	O
around	O
different	O
implementations	B-Application
.	O
</s>
<s>
Code	O
that	O
strictly	O
conforms	O
to	O
the	O
ISO-Prolog	O
core	O
language	O
is	O
portable	O
across	O
ISO-compliant	O
implementations	B-Application
.	O
</s>
<s>
However	O
,	O
the	O
ISO	O
standard	O
for	O
modules	O
was	O
never	O
accepted	O
by	O
most	O
Prolog	B-Language
implementors	O
.	O
</s>
<s>
Use	O
of	O
libraries	O
unavailable	O
in	O
other	O
implementations	B-Application
and	O
library	O
organisation	O
:	O
</s>
<s>
Platform	O
Features	O
Toolkit	O
Prolog	B-Language
Mechanics	O
Name	O
OS	O
Licence	O
Native	O
Graphics	O
Compiled	O
Code	O
Unicode	O
Object	O
Oriented	O
Native	O
OS	O
Control	O
Stand	O
Alone	O
Executable	O
C	O
Interface	O
Java	O
Interface	O
Interactive	O
Interpreter	O
Debugger	O
Code	O
Profiler	O
SyntaxAllegroPrologUnix	O
,	O
Windows	B-Application
,	O
Mac	B-Application
OS	I-Application
XCommercial	O
,	O
limited	O
free	O
edition	O
available	O
,	O
via	O
Lisp	O
,	O
via	O
Lisp	O
,	O
via	O
Lisp	O
,	O
via	O
LispS-expressions	O
.	O
</s>
