<s>
Meurs	B-Protocol
Challenger	I-Protocol
is	O
an	O
online	O
graph	O
visualization	B-Application
program	O
,	O
with	O
data	O
analysis	O
and	O
browsing	O
.	O
</s>
<s>
The	O
software	O
supports	O
several	O
graph	O
layout	B-Algorithm
algorithms	I-Algorithm
,	O
and	O
allows	O
the	O
user	O
to	O
interact	O
with	O
the	O
nodes	O
.	O
</s>
<s>
Written	O
in	O
ActionScript	B-Operating_System
,	O
the	O
program	O
runs	O
on	O
Windows	O
,	O
Linux	B-Application
,	O
macOS	B-Application
and	O
other	O
platforms	O
that	O
support	O
the	O
Adobe	B-Operating_System
Flash	I-Operating_System
Player	I-Operating_System
.	O
</s>
<s>
Meurs	B-Protocol
Challenger	I-Protocol
was	O
the	O
winner	O
at	O
the	O
2011	O
edition	O
of	O
the	O
International	O
Symposium	O
on	O
Graph	O
Drawing	O
,	O
in	O
the	O
large	O
graph	O
category	O
.	O
</s>
<s>
The	O
main	O
problem	O
in	O
network	O
visualization	B-Application
is	O
to	O
reduce	O
data	O
complexity	O
by	O
projecting	O
a	O
multivariate	O
data	O
matrix	O
onto	O
a	O
lower-dimensional	O
planar	O
display	O
space	O
,	O
which	O
is	O
achieved	O
by	O
proper	O
node	O
positioning	O
.	O
</s>
<s>
Meurs	B-Protocol
Challenger	I-Protocol
addresses	O
this	O
by	O
combining	O
several	O
different	O
approaches	O
:	O
</s>
