<s>
Critter	B-Application
is	O
a	O
cross-platform	B-Operating_System
UCI	B-General_Concept
chess	B-Application
engine	I-Application
by	O
Slovakian	O
programmer	B-Application
Richard	O
Vida	O
which	O
is	O
free	O
for	O
non-commercial	O
use	O
.	O
</s>
<s>
The	O
engine	O
has	O
achieved	O
top	O
five	O
on	O
most	O
official	O
chess	B-Application
engine	I-Application
Elo	O
rating	O
lists	O
.	O
</s>
<s>
Richard	O
Vida	O
started	O
working	O
on	O
Critter	B-Application
in	O
late	O
2008	O
.	O
</s>
<s>
The	O
first	O
version	O
was	O
originally	O
written	O
in	O
Object	B-Language
Pascal	I-Language
but	O
the	O
code	O
was	O
later	O
converted	O
to	O
C++	B-Language
using	O
Bitboard	B-Application
technology	O
because	O
Delphi	B-Language
did	O
not	O
perform	O
well	O
under	O
64-bit	B-Device
processors	I-Device
.	O
</s>
<s>
Critter	B-Application
had	O
its	O
over-the-board	O
(	O
OTB	O
)	O
debut	O
at	O
the	O
ICT	O
2012	O
,	O
where	O
it	O
became	O
a	O
strong	O
runner-up	O
behind	O
the	O
Rybka	B-Application
cluster	O
.	O
</s>
<s>
Critter	B-Application
sacs	O
two	O
pawns	O
and	O
the	O
exchange	O
to	O
build	O
up	O
a	O
strong	O
attack	O
.	O
</s>
