<s>
TerminusDB	B-Application
is	O
an	O
open	B-License
source	I-License
knowledge	B-Application
graph	I-Application
and	O
document	B-General_Concept
store	I-General_Concept
.	O
</s>
<s>
It	O
is	O
a	O
native	B-Language
revision	B-Architecture
control	I-Architecture
database	O
that	O
is	O
architecturally	O
similar	O
to	O
Git	B-Application
.	O
</s>
<s>
It	O
is	O
listed	O
on	O
DB-Engines	B-Application
.	O
</s>
<s>
TerminusDB	B-Application
provides	O
a	O
document	O
API	B-Application
for	O
building	O
via	O
the	O
JSON	O
exchange	O
format	O
.	O
</s>
<s>
It	O
implements	O
both	O
GraphQL	B-Language
and	O
a	O
datalog	B-Language
variant	O
called	O
WOQL	O
.	O
</s>
<s>
TerminusDB	B-Application
is	O
available	O
under	O
the	O
Apache	B-Application
2.0	I-Application
license	I-Application
.	O
</s>
<s>
TerminusDB	B-Application
is	O
implemented	O
in	O
Prolog	B-Language
and	O
Rust	B-Application
.	O
</s>
<s>
TerminusDB	B-Application
,	O
previously	O
known	O
as	O
DataChemist	O
,	O
was	O
founded	O
in	O
Dublin	O
,	O
Ireland	O
.	O
</s>
<s>
Starting	O
in	O
Trinity	O
College	O
Dublin	O
,	O
the	O
development	O
team	O
behind	O
TerminusDB	B-Application
ran	O
the	O
Horizon	O
2020	O
project	O
ALIGNED	O
that	O
worked	O
from	O
February	O
2015	O
to	O
January	O
2018	O
.	O
</s>
<s>
TerminusDB	B-Application
was	O
first	O
released	O
under	O
the	O
GPLv3	B-License
license	O
with	O
the	O
client	B-Protocol
libraries	O
released	O
with	O
the	O
Apache	B-Application
2	I-Application
license	I-Application
.	O
</s>
<s>
With	O
v4.0	O
,	O
which	O
was	O
released	O
in	O
December	O
2020	O
,	O
TerminusDB	B-Application
switched	O
to	O
the	O
Apache	B-Application
2.0	I-Application
license	I-Application
.	O
</s>
<s>
TerminusDB	B-Application
is	O
named	O
after	O
the	O
Roman	O
God	O
of	O
Boundaries	O
,	O
Terminus	O
.	O
</s>
<s>
TerminusDB	B-Application
is	O
an	O
in-memory	B-General_Concept
graph	B-Application
database	I-Application
management	O
system	O
with	O
a	O
rich	O
query	O
language	O
.	O
</s>
<s>
The	O
design	O
of	O
the	O
underlying	O
data	B-General_Concept
structure	I-General_Concept
,	O
which	O
is	O
implemented	O
in	O
a	O
Rust	B-Application
library	B-Library
,	O
uses	O
a	O
succinct	B-Data_Structure
data	I-Data_Structure
structures	I-Data_Structure
and	O
delta	B-Algorithm
encoding	I-Algorithm
approach	O
drawing	O
inspiration	O
from	O
software	O
source	B-Architecture
control	I-Architecture
systems	O
like	O
Git	B-Application
.	O
</s>
<s>
This	O
allows	O
all	O
of	O
the	O
Git	B-Application
semantics	B-Application
to	O
be	O
used	O
in	O
TerminusDB	B-Application
.	O
</s>
<s>
TerminusDB	B-Application
is	O
based	O
on	O
the	O
RDF	O
standard	O
.	O
</s>
<s>
This	O
standard	O
specifies	O
finite	O
labelled	O
directed	O
graphs	O
which	O
are	O
parameterized	B-General_Concept
in	O
some	O
universe	O
of	O
datatypes	O
.	O
</s>
<s>
The	O
names	O
for	O
nodes	O
and	O
labels	O
are	O
drawn	O
from	O
a	O
set	O
of	O
IRIs	O
(	O
Internationalized	B-Protocol
Resource	I-Protocol
Identifiers	I-Protocol
)	O
.	O
</s>
<s>
TerminusDB	B-Application
uses	O
the	O
XSD	O
datatypes	O
as	O
its	O
universe	O
of	O
concrete	O
values	O
.	O
</s>
<s>
For	O
schema	B-Application
design	O
,	O
TerminusDB	B-Application
used	O
the	O
OWL	B-Language
language	I-Language
until	O
version	O
10.0	O
.	O
</s>
<s>
Since	O
version	O
10	O
it	O
uses	O
a	O
JSON	O
schema	B-Application
interface	O
allowing	O
users	O
to	O
build	O
schemas	O
using	O
a	O
simple	O
JSON	O
format	O
.	O
</s>
<s>
This	O
provides	O
a	O
rich	O
modelling	O
language	O
which	O
enables	O
constraints	B-Application
on	O
the	O
allowable	O
shapes	O
in	O
the	O
graph	O
.	O
</s>
<s>
TerminusDB	B-Application
has	O
a	O
promise	O
based	O
client	B-Protocol
for	O
the	O
browser	B-Application
and	O
node.js	B-Language
it	O
is	O
available	O
through	O
the	O
npm	B-Language
registry	O
,	O
or	O
can	O
be	O
directly	O
included	O
in	O
web-sites	O
.	O
</s>
<s>
It	O
also	O
has	O
a	O
Python	B-Language
client	B-Protocol
for	O
the	O
TerminusDB	B-Application
RESTful	B-Protocol
API	I-Protocol
and	O
a	O
python	B-Language
version	O
of	O
the	O
web	O
object	O
query	O
language	O
,	O
WOQLpy	O
.	O
</s>
<s>
GraphQL	B-Language
is	O
implemented	O
to	O
allow	O
users	O
to	O
query	O
TerminusDB	B-Application
projects	O
in	O
such	O
a	O
way	O
that	O
deep	O
linking	O
can	O
be	O
discovered	O
.	O
</s>
<s>
WOQL	O
(	O
web	O
object	O
query	O
language	O
)	O
is	O
a	O
datalog-based	O
query	O
language	O
.	O
</s>
<s>
It	O
allows	O
TerminusDB	B-Application
to	O
treat	O
the	O
database	O
as	O
a	O
document	B-General_Concept
store	I-General_Concept
or	O
a	O
graph	O
interchangeably	O
,	O
and	O
provides	O
query	O
features	O
to	O
make	O
relationship	O
traversals	O
easy	O
.	O
</s>
<s>
This	O
gives	O
a	O
relatively	O
straightforward	O
human-readable	O
format	O
which	O
can	O
be	O
easily	O
stored	O
in	O
TerminusDB	B-Application
itself	O
.	O
</s>
<s>
A	O
simple	O
query	O
which	O
creates	O
a	O
document	O
in	O
the	O
database	O
,	O
along	O
with	O
labels	O
and	O
cardinality	B-Application
constraints	I-Application
.	O
</s>
<s>
TerminusCMS	O
is	O
a	O
headless	B-Protocol
open-source	B-License
content	B-Protocol
management	I-Protocol
system	I-Protocol
that	O
uses	O
a	O
model-driven	B-Architecture
,	O
API-first	O
approach	O
to	O
content	O
management	O
.	O
</s>
<s>
The	O
CMS	O
is	O
built	O
on	O
TerminusDB	B-Application
and	O
focused	O
on	O
software	B-General_Concept
engineer	I-General_Concept
users	O
.	O
</s>
