<s>
The	O
Open	B-Language
Semantic	I-Language
Framework	I-Language
(	O
OSF	O
)	O
is	O
an	O
integrated	O
software	B-Application
stack	I-Application
using	O
semantic	O
technologies	O
for	O
knowledge	O
management	O
.	O
</s>
<s>
It	O
has	O
a	O
layered	O
architecture	B-Architecture
that	O
combines	O
existing	O
open	B-Application
source	I-Application
software	I-Application
with	O
additional	O
open	B-Application
source	I-Application
components	O
developed	O
specifically	O
to	O
provide	O
a	O
complete	O
Web	B-Application
application	I-Application
framework	I-Application
.	O
</s>
<s>
OSF	O
is	O
made	O
available	O
under	O
the	O
Apache	B-Application
2	I-Application
license	I-Application
.	O
</s>
<s>
OSF	O
is	O
a	O
platform-independent	O
Web	O
services	O
framework	O
for	O
accessing	O
and	O
exposing	O
structured	B-General_Concept
data	I-General_Concept
,	O
semi-structured	B-Application
data	I-Application
,	O
and	O
unstructured	B-Application
data	I-Application
using	O
ontologies	B-Language
to	O
reconcile	O
semantic	O
heterogeneities	O
within	O
the	O
contributing	O
data	O
and	O
schema	B-Application
.	O
</s>
<s>
Internal	O
to	O
OSF	O
,	O
all	O
data	O
is	O
converted	O
to	O
RDF	O
to	O
provide	O
a	O
common	B-Application
data	I-Application
model	I-Application
.	O
</s>
<s>
The	O
OWL	B-Language
2	I-Language
ontology	B-Language
language	I-Language
is	O
used	O
to	O
describe	O
the	O
data	O
schema	B-Application
overlaying	O
all	O
of	O
the	O
constituent	O
data	O
sources	O
.	O
</s>
<s>
The	O
architecture	B-Architecture
of	O
OSF	O
is	O
built	O
around	O
a	O
central	O
layer	O
of	O
RESTful	B-Protocol
web	I-Protocol
services	I-Protocol
,	O
designed	O
to	O
enable	O
most	O
constituent	O
modules	O
within	O
the	O
software	B-Application
stack	I-Application
to	O
be	O
substituted	O
without	O
major	O
adverse	O
impacts	O
on	O
the	O
entire	O
stack	O
.	O
</s>
<s>
A	O
central	O
organizing	O
perspective	O
of	O
OSF	O
is	O
that	O
of	O
the	O
dataset	B-General_Concept
.	O
</s>
<s>
These	O
datasets	B-General_Concept
contain	O
the	O
records	O
in	O
any	O
given	O
OSF	O
instance	O
.	O
</s>
<s>
One	O
or	O
more	O
domain	O
ontologies	B-Language
is	O
used	O
by	O
a	O
given	O
OSF	O
instance	O
to	O
define	O
the	O
structural	O
relationships	O
amongst	O
the	O
data	O
and	O
their	O
attributes	O
and	O
concepts	O
.	O
</s>
<s>
Some	O
of	O
the	O
use	O
applications	O
for	O
OSF	O
include	O
local	O
government	O
,	O
health	O
information	O
systems	O
,	O
community	O
indicator	O
systems	O
,	O
eLearning	O
,	O
citizen	O
engagement	O
,	O
or	O
any	O
domain	O
that	O
may	O
be	O
modeled	O
by	O
ontologies	B-Language
.	O
</s>
<s>
Documentation	O
and	O
training	O
videos	O
are	O
provided	O
with	O
the	O
open-source	B-Application
OSF	O
application	O
.	O
</s>
<s>
OSF	O
was	O
expanded	O
with	O
an	O
ontology	B-Language
manager	O
,	O
structOntology	O
in	O
August	O
2012	O
.	O
</s>
<s>
The	O
Open	B-Language
Semantic	I-Language
Framework	I-Language
has	O
a	O
basic	O
three-layer	O
architecture	B-Architecture
.	O
</s>
<s>
User	O
interactions	O
and	O
content	O
management	O
are	O
provided	O
by	O
an	O
external	O
content	B-Protocol
management	I-Protocol
system	I-Protocol
,	O
which	O
is	O
currently	O
Drupal	B-Application
(	O
but	O
does	O
not	O
depend	O
on	O
it	O
)	O
.	O
</s>
<s>
This	O
layer	O
accesses	O
the	O
pivotal	O
;	O
there	O
are	O
now	O
more	O
than	O
20	O
providing	O
OSF	O
's	O
distributed	B-Architecture
computing	I-Architecture
functionality	O
.	O
</s>
<s>
Full	O
CRUD	B-General_Concept
access	O
and	O
user	O
permissions	O
and	O
security	O
is	O
provided	O
to	O
all	O
digital	O
objects	O
in	O
the	O
stack	O
.	O
</s>
<s>
This	O
middleware	B-General_Concept
layer	O
then	O
provides	O
a	O
means	O
to	O
access	O
the	O
third	O
layer	O
,	O
the	O
engines	O
and	O
indexers	O
that	O
drive	O
the	O
entire	O
stack	O
.	O
</s>
<s>
Both	O
the	O
top	O
CMS	B-Protocol
layer	O
and	O
the	O
engines	O
layer	O
are	O
provided	O
by	O
existing	O
off-the-shelf	O
software	O
.	O
</s>
<s>
RDF	O
provides	O
the	O
means	O
for	O
integrating	O
existing	O
structured	B-General_Concept
data	I-General_Concept
assets	O
in	O
any	O
format	O
,	O
with	O
semi-structured	B-Application
data	I-Application
like	O
XML	B-Protocol
and	O
HTML	O
,	O
and	O
unstructured	O
documents	O
or	O
text	O
.	O
</s>
<s>
The	O
OSF	O
framework	O
is	O
made	O
operational	O
via	O
ontologies	B-Language
that	O
capture	O
the	O
domain	O
or	O
knowledge	O
space	O
,	O
matched	O
with	O
internal	O
ontologies	B-Language
that	O
guide	O
OSF	O
operations	O
and	O
data	O
display	O
.	O
</s>
<s>
This	O
design	O
approach	O
is	O
known	O
as	O
ODapps	O
,	O
for	O
ontology-driven	O
applications	O
.	O
</s>
<s>
OSF	O
delegates	O
all	O
direct	O
user	O
interactions	O
and	O
standard	O
content	O
management	O
to	O
an	O
external	O
CMS	B-Protocol
.	O
</s>
<s>
In	O
the	O
case	O
of	O
Drupal	B-Application
,	O
this	O
integration	O
is	O
tighter	O
,	O
and	O
supports	O
connectors	O
and	O
modules	O
that	O
can	O
replace	O
standard	O
Drupal	B-Application
storage	O
and	O
databases	O
with	O
OSF	O
triplestores	O
.	O
</s>
<s>
This	O
intermediate	O
OSF	O
Web	O
Services	O
layer	O
may	O
also	O
be	O
accessed	O
directly	O
via	O
API	B-Application
or	O
command	O
line	O
or	O
utilities	O
like	O
cURL	B-Language
,	O
suitable	O
for	O
interfacing	O
with	O
standard	O
content	B-Protocol
management	I-Protocol
systems	I-Protocol
(	O
CMSs	O
)	O
,	O
or	O
via	O
a	O
dedicated	O
suite	O
of	O
connectors	O
and	O
modules	O
that	O
leverage	O
the	O
open	B-Application
source	I-Application
Drupal	B-Application
CMS	B-Protocol
.	O
</s>
<s>
These	O
connectors	O
and	O
modules	O
,	O
also	O
part	O
of	O
the	O
standard	O
OSF	O
stack	O
and	O
called	O
,	O
natively	O
enable	O
Drupal	B-Application
's	O
existing	O
thousands	O
of	O
modules	O
and	O
ecosystem	O
of	O
developers	O
and	O
capabilities	O
to	O
access	O
OSF	O
using	O
familiar	O
Drupal	B-Application
methods	O
.	O
</s>
<s>
The	O
OSF	O
middleware	B-General_Concept
framework	O
is	O
generally	O
RESTful	B-Protocol
in	O
design	O
and	O
is	O
based	O
on	O
HTTP	B-Protocol
and	O
Web	O
protocols	O
and	O
W3C	O
open	O
standards	O
.	O
</s>
<s>
The	O
initial	O
OSF	O
framework	O
comes	O
packaged	O
with	O
a	O
baseline	O
set	O
of	O
more	O
than	O
20	O
Web	O
services	O
in	O
CRUD	B-General_Concept
,	O
browse	O
,	O
search	O
,	O
tagging	O
,	O
ontology	B-Language
management	O
,	O
and	O
export	O
and	O
import	O
.	O
</s>
<s>
All	O
Web	O
services	O
are	O
exposed	O
via	O
APIs	B-Application
and	O
SPARQL	B-Language
endpoints	I-Language
.	O
</s>
<s>
Each	O
request	O
to	O
an	O
individual	O
Web	O
service	O
returns	O
an	O
HTTP	B-Protocol
status	O
and	O
optionally	O
a	O
document	O
of	O
resultsets	O
.	O
</s>
<s>
Each	O
results	O
document	O
can	O
be	O
serialized	O
in	O
many	O
ways	O
,	O
and	O
may	O
be	O
expressed	O
as	O
either	O
RDF	O
,	O
pure	O
XML	B-Protocol
,	O
JSON	B-General_Concept
,	O
or	O
other	O
formats	O
.	O
</s>
<s>
The	O
engines	O
layer	O
represents	O
the	O
major	O
workflow	O
requirements	O
and	O
data	B-General_Concept
management	I-General_Concept
and	O
indexing	O
of	O
the	O
system	O
.	O
</s>
<s>
The	O
premise	O
of	O
the	O
Open	B-Language
Semantic	I-Language
Framework	I-Language
is	O
based	O
on	O
the	O
RDF	O
data	O
model	O
.	O
</s>
<s>
Using	O
a	O
common	B-Application
data	I-Application
model	I-Application
means	O
that	O
all	O
Web	O
services	O
and	O
actions	O
against	O
the	O
data	O
only	O
need	O
to	O
be	O
programmed	O
via	O
a	O
single	O
,	O
canonical	O
form	O
.	O
</s>
<s>
The	O
OSF	O
engines	O
are	O
all	O
open	B-Application
source	I-Application
and	O
work	O
to	O
support	O
this	O
premise	O
.	O
</s>
<s>
Documents	O
are	O
indexed	O
by	O
the	O
Solr	B-Language
engine	O
for	O
full-text	O
search	O
,	O
while	O
information	O
about	O
their	O
structural	O
characteristics	O
and	O
metadata	O
are	O
stored	O
in	O
an	O
RDF	O
triplestore	O
database	O
provided	O
by	O
OpenLink	O
's	O
Virtuoso	B-Application
software	O
.	O
</s>
<s>
The	O
schema	B-Application
aspects	O
of	O
the	O
information	O
(	O
the	O
"	O
ontologies	B-Language
"	O
)	O
are	O
separately	O
managed	O
and	O
manipulated	O
with	O
their	O
own	O
W3C	O
standard	O
application	O
,	O
the	O
.	O
</s>
<s>
Another	O
engine	O
,	O
GATE	O
(	O
General	B-Language
Architecture	I-Language
for	I-Language
Text	I-Language
Engineering	I-Language
)	O
,	O
provides	O
semi-automatic	O
assistance	O
in	O
tagging	O
input	O
information	O
and	O
other	O
natural	B-Language
language	I-Language
processing	I-Language
(	O
NLP	B-Language
)	O
tasks	O
.	O
</s>
<s>
OSF	O
is	O
sometimes	O
referred	O
to	O
as	O
a	O
linked	B-Operating_System
data	I-Operating_System
application	I-Operating_System
.	O
</s>
<s>
The	O
Open	B-Language
Semantic	I-Language
Framework	I-Language
also	O
has	O
alternatives	O
in	O
the	O
semantic	O
publishing	O
and	O
semantic	B-General_Concept
computing	I-General_Concept
arenas	O
.	O
</s>
