<s>
WHAT	O
IF	O
is	O
a	O
computer	B-Application
program	I-Application
used	O
in	O
a	O
wide	O
variety	O
of	O
computational	O
(	O
in	O
silico	O
)	O
macromolecular	O
structure	O
research	O
fields	O
.	O
</s>
<s>
The	O
first	O
version	O
of	O
the	O
WHAT	B-Application
IF	I-Application
software	I-Application
was	O
developed	O
by	O
Gert	O
Vriend	O
in	O
1987	O
at	O
the	O
University	O
of	O
Groningen	O
,	O
Groningen	O
,	O
Netherlands	O
.	O
</s>
<s>
WHAT	O
IF	O
is	O
compatible	O
with	O
several	O
other	O
bioinformatics	O
software	O
packages	O
,	O
including	O
YASARA	B-Application
and	O
Jmol	B-Language
.	O
</s>
