<s>
GraphHopper	B-Language
is	O
an	O
open-source	B-Application
routing	B-Protocol
library	O
and	O
server	O
written	O
in	O
Java	B-Language
and	O
provides	O
a	O
web	O
interface	O
called	O
GraphHopper	B-Language
Maps	O
as	O
well	O
as	O
a	O
routing	B-Protocol
API	O
over	O
HTTP	O
.	O
</s>
<s>
It	O
runs	O
on	O
the	O
server	O
,	O
desktop	O
,	O
Android	B-Application
,	O
iOS	B-Application
or	O
Raspberry	B-Operating_System
Pi	I-Operating_System
.	O
</s>
<s>
By	O
default	O
OpenStreetMap	O
data	O
for	O
the	O
road	O
network	O
and	O
elevation	O
data	O
from	O
the	O
Shuttle	B-Algorithm
Radar	I-Algorithm
Topography	I-Algorithm
Mission	I-Algorithm
is	O
used	O
.	O
</s>
<s>
GraphHopper	B-Language
can	O
be	O
configured	O
to	O
use	O
different	O
algorithms	O
such	O
as	O
Dijkstra	B-Algorithm
,	O
A*	B-Protocol
and	O
its	O
bidirectional	B-Algorithm
versions	I-Algorithm
.	O
</s>
<s>
To	O
make	O
routing	B-Protocol
fast	O
enough	O
for	O
long	O
paths	O
(	O
continental	O
size	O
)	O
and	O
avoid	O
heuristical	O
approaches	O
GraphHopper	B-Language
uses	O
contraction	B-Protocol
hierarchies	I-Protocol
by	O
default	O
.	O
</s>
<s>
In	O
the	O
Java	B-Language
Magazine	O
from	O
Oracle	B-Application
,	O
the	O
author	O
,	O
Peter	O
Karich	O
,	O
describes	O
the	O
techniques	O
necessary	O
to	O
make	O
the	O
system	O
memory	O
efficient	O
and	O
fast	O
.	O
</s>
<s>
Furthermore	O
,	O
GraphHopper	B-Language
is	O
built	O
on	O
a	O
large	O
test	O
suite	O
including	O
unit	O
,	O
integration	O
and	O
load	O
tests	O
.	O
</s>
<s>
The	O
Apache	B-Application
License	I-Application
allows	O
everyone	O
to	O
customize	O
and	O
integrate	O
GraphHopper	B-Language
in	O
free	O
or	O
commercial	O
products	O
,	O
and	O
together	O
with	O
the	O
query	O
speed	O
and	O
OpenStreetMap	O
data	O
this	O
makes	O
GraphHopper	B-Language
a	O
possible	O
alternative	O
to	O
existing	O
routing	B-Protocol
services	O
and	O
GPS	B-Application
navigation	I-Application
software	I-Application
.	O
</s>
<s>
Besides	O
point-to-point	O
routing	B-Protocol
for	O
different	O
vehicles	O
GraphHopper	B-Language
can	O
be	O
used	O
to	O
calculate	O
distance	O
matrices	O
which	O
are	O
then	O
used	O
as	O
an	O
input	O
for	O
vehicle	B-Algorithm
routing	I-Algorithm
problems	I-Algorithm
.	O
</s>
<s>
Track	O
vehicles	O
via	O
map	B-General_Concept
matching	I-General_Concept
-	O
i.e.	O
</s>
<s>
Notable	O
users	O
of	O
GraphHopper	B-Language
are	O
Rome2rio	B-Application
,	O
Deutsche	O
Bahn	O
,	O
Komoot	B-Application
,	O
Gnome	O
and	O
Flixbus	O
.	O
</s>
<s>
Since	O
February	O
2015	O
,	O
GraphHopper	B-Language
has	O
been	O
one	O
of	O
the	O
APIs	O
powering	O
routing	B-Protocol
on	O
the	O
official	O
OpenStreetMap	O
website	O
and	O
version	O
0.4	O
was	O
released	O
shortly	O
afterwards	O
in	O
March	O
2015	O
.	O
</s>
<s>
In	O
January	O
2016	O
,	O
the	O
developers	O
of	O
GraphHopper	B-Language
and	O
jsprit	O
formed	O
the	O
company	O
GraphHopper	B-Language
GmbH	O
.	O
</s>
