<s>
Marble	B-Application
is	O
a	O
virtual	B-Application
globe	I-Application
application	O
which	O
allows	O
the	O
user	O
to	O
choose	O
among	O
the	O
Earth	O
,	O
the	O
Moon	O
,	O
Venus	O
,	O
Mars	O
and	O
other	O
planets	O
to	O
display	O
as	O
a	O
3-D	O
model	O
.	O
</s>
<s>
It	O
is	O
free	B-Application
software	I-Application
under	O
the	O
terms	O
of	O
the	O
GNU	B-Application
LGPL	I-Application
,	O
developed	O
by	O
KDE	B-Application
for	O
use	O
on	O
personal	B-Device
computers	I-Device
and	O
smart	B-Application
phones	I-Application
.	O
</s>
<s>
It	O
is	O
written	O
in	O
C++	B-Language
and	O
uses	O
Qt	B-Language
.	O
</s>
<s>
Marble	B-Application
is	O
intended	O
to	O
be	O
very	O
flexible	O
;	O
beyond	O
its	O
cross-platform	O
design	O
,	O
the	O
core	O
components	O
can	O
easily	O
be	O
integrated	O
into	O
other	O
programs	O
.	O
</s>
<s>
It	O
is	O
designed	O
to	O
run	O
without	O
the	O
need	O
for	O
hardware	O
acceleration	O
,	O
but	O
it	O
can	O
be	O
extended	O
to	O
use	O
OpenGL	B-Application
.	O
</s>
<s>
Contributors	O
have	O
added	O
support	O
for	O
on-line	O
mapping	O
sources	O
such	O
as	O
OpenStreetMap	O
and	O
the	O
ability	O
to	O
interpret	O
KML	B-Application
files	O
.	O
</s>
<s>
Marble	B-Application
also	O
provides	O
route	B-Application
planning	I-Application
capabilities	O
.	O
</s>
<s>
A	O
navigation	B-Application
mode	I-Application
called	O
MarbleToGo	O
was	O
developed	O
as	O
part	O
of	O
Google	B-Application
Summer	I-Application
of	I-Application
Code	I-Application
2010	I-Application
.	O
</s>
<s>
It	O
was	O
later	O
partially	O
rewritten	O
and	O
renamed	O
to	O
Marble	B-Application
Touch	O
.	O
</s>
<s>
Geothek	B-Application
is	O
a	O
fork	B-Application
of	O
Marble	B-Application
adding	O
a	O
statistics	O
module	O
,	O
pixel	O
maps	O
,	O
and	O
a	O
3D	O
view	O
.	O
</s>
