<s>
Ontotext	B-Application
GraphDB	I-Application
(	O
previously	O
known	O
as	O
BigOWLIM	O
)	O
is	O
a	O
graph	B-Application
database	I-Application
and	O
knowledge	O
discovery	O
tool	O
compliant	O
with	O
RDF	O
and	O
SPARQL	B-Language
and	O
available	O
as	O
a	O
high-availability	O
cluster	O
.	O
</s>
<s>
Ontotext	B-Application
GraphDB	I-Application
is	O
used	O
in	O
various	O
European	O
research	O
projects	O
.	O
</s>
<s>
In	O
2014	O
Ontotext	O
acquired	O
the	O
trademark	O
"	O
GraphDB	B-Application
"	O
from	O
Sones	O
.	O
</s>
<s>
GraphDB	B-Application
is	O
used	O
to	O
store	O
and	O
manage	O
semantic	O
Knowledge	B-Application
Graph	I-Application
data	O
.	O
</s>
<s>
The	O
Engine	O
consists	O
of	O
a	O
query	B-Language
optimizer	I-Language
,	O
reasoner	O
,	O
storage	O
and	O
plugin	O
manager	O
.	O
</s>
<s>
The	O
reasoner	O
in	O
GraphDB	B-Application
is	O
Forward	O
chaining	O
with	O
the	O
goal	O
of	O
total	O
materialization	O
.	O
</s>
<s>
GeoSPARQL	B-General_Concept
,	O
which	O
is	O
the	O
standard	O
for	O
geographical	O
linked	B-Operating_System
data	I-Operating_System
.	O
</s>
<s>
Lucene	B-Language
,	O
which	O
supports	O
full-text	O
search	O
capabilities	O
.	O
</s>
<s>
GraphDB	B-Application
has	O
a	O
connector	O
for	O
both	O
well-known	O
open-source	B-Application
search	O
engines	O
,	O
Solr	B-Language
and	O
Elasticsearch	B-Application
.	O
</s>
<s>
There	O
is	O
also	O
a	O
connector	O
enabling	O
MongoDB	B-Application
integration	O
,	O
providing	O
the	O
scalability	O
and	O
performance	O
advantages	O
.	O
</s>
<s>
Kafka	B-Language
Sink	O
Connector	O
for	O
ingesting	O
large	O
amounts	O
of	O
data	O
.	O
</s>
<s>
GraphQL	B-Language
access	O
to	O
knowledge	B-Application
graphs	I-Application
and	O
semantic	O
search	O
based	O
on	O
Elasticsearch	B-Application
and	O
exposed	O
through	O
GraphQL	B-Language
.	O
</s>
<s>
GraphDB	B-Application
uses	O
RDF4J	O
as	O
a	O
library	O
,	O
utilizing	O
its	O
APIs	B-Application
for	O
storage	O
and	O
querying	O
.	O
</s>
<s>
It	O
supports	O
the	O
GraphQL	B-Language
,	O
SPARQL	B-Language
and	O
SeRQL	O
languages	O
and	O
RDF	O
(	O
e.g.	O
,	O
RDF/XML	O
,	O
N3	O
,	O
Turtle	O
)	O
serialization	O
formats	O
.	O
</s>
<s>
It	O
supports	O
custom	O
reasoning	O
rulesets	O
,	O
as	O
well	O
as	O
RDFS	O
,	O
RDFS-plus	O
,	O
OWL	B-Language
2	I-Language
RL	O
and	O
QL	O
.	O
</s>
<s>
It	O
integrates	O
OpenRefine	B-Application
for	O
the	O
ingestion	O
of	O
tabular	O
data	O
and	O
provides	O
semantic	O
similarity	O
search	O
at	O
the	O
document	O
level	O
.	O
</s>
<s>
For	O
more	O
examples	O
see	O
"	O
Diverse	O
Uses	O
of	O
a	O
Semantic	O
Graph	B-Application
Database	I-Application
for	O
Knowledge	O
Organization	O
and	O
Research	O
"	O
below	O
.	O
</s>
