<s>
Content	B-Protocol
Repository	I-Protocol
API	I-Protocol
for	I-Protocol
Java	I-Protocol
(	O
JCR	O
)	O
is	O
a	O
specification	O
for	O
a	O
Java	B-Device
platform	I-Device
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
to	O
access	O
content	B-Protocol
repositories	I-Protocol
in	O
a	O
uniform	O
manner	O
.	O
</s>
<s>
The	O
content	B-Protocol
repositories	I-Protocol
are	O
used	O
in	O
content	B-Protocol
management	I-Protocol
systems	I-Protocol
to	O
keep	O
the	O
content	O
data	O
and	O
also	O
the	O
metadata	O
used	O
in	O
content	B-Protocol
management	I-Protocol
systems	I-Protocol
(	O
CMS	O
)	O
such	O
as	O
versioning	O
metadata	O
.	O
</s>
<s>
The	O
specification	O
was	O
developed	O
under	O
the	O
Java	B-Language
Community	I-Language
Process	I-Language
as	O
JSR-170	B-Protocol
(	O
Version	O
1	O
)	O
,	O
and	O
as	O
JSR-283	O
(	O
version	O
2	O
)	O
.	O
</s>
<s>
The	O
main	O
Java	B-Language
package	I-Language
is	O
javax.jcr	O
.	O
</s>
<s>
A	O
JCR	O
is	O
a	O
type	O
of	O
object	B-Application
database	I-Application
tailored	O
to	O
storing	O
,	O
searching	O
,	O
and	O
retrieving	O
hierarchical	O
data	O
.	O
</s>
<s>
The	O
JCR	O
API	B-Application
grew	O
out	O
of	O
the	O
needs	O
of	O
content	B-Protocol
management	I-Protocol
systems	I-Protocol
,	O
which	O
require	O
storing	O
documents	O
and	O
other	O
binary	O
objects	O
with	O
associated	O
metadata	O
;	O
however	O
,	O
the	O
API	B-Application
is	O
applicable	O
to	O
many	O
additional	O
types	O
of	O
applications	O
.	O
</s>
<s>
In	O
addition	O
to	O
object	O
storage	O
,	O
the	O
JCR	O
provides	O
:	O
APIs	B-Application
for	O
versioning	O
of	O
data	O
;	O
transactions	B-General_Concept
;	O
observation	O
of	O
changes	O
in	O
data	O
;	O
and	O
import	O
or	O
export	O
of	O
data	O
to	O
XML	B-Protocol
in	O
a	O
standard	O
way	O
.	O
</s>
<s>
In	O
this	O
way	O
nodes	O
in	O
a	O
JCR	O
offer	O
both	O
referential	B-General_Concept
integrity	I-General_Concept
and	O
object-oriented	O
concept	O
of	O
inheritance	B-Language
.	O
</s>
<s>
A	O
JCR	O
can	O
export	O
portions	O
of	O
its	O
tree	O
to	O
XML	B-Protocol
in	O
two	O
standard	O
formats	O
and	O
can	O
import	O
hierarchies	O
directly	O
from	O
XML	B-Protocol
.	O
</s>
<s>
JSR	O
283	O
compliant	O
implementations	O
must	O
support	O
a	O
standardized	O
form	O
of	O
SQL	B-Language
for	O
queries	O
and	O
a	O
query	O
object	O
model	O
QOM	O
.	O
</s>
<s>
JSR	O
283	O
deprecates	O
the	O
XPath	B-Language
query	O
language	O
defined	O
in	O
JSR	B-Protocol
170	I-Protocol
.	O
</s>
<s>
The	O
Apache	B-Language
Jackrabbit	I-Language
reference	O
implementation	O
of	O
JCR	O
also	O
supports	O
the	O
integration	O
of	O
the	O
Apache	B-Language
Lucene	I-Language
search	O
engine	O
to	O
give	O
full	O
text	O
searches	O
of	O
data	O
in	O
the	O
repository	O
.	O
</s>
<s>
Day	O
had	O
both	O
a	O
commercial	O
JCR	O
implementation	O
called	O
Content	B-Protocol
Repository	I-Protocol
Extreme	O
(	O
CRX	O
)	O
and	O
was	O
involved	O
in	O
the	O
open	O
source	O
Apache	B-Language
Jackrabbit	I-Language
JCR	O
,	O
which	O
had	O
its	O
2.0	O
release	O
in	O
January	O
2010	O
.	O
</s>
<s>
Jahia	B-Application
,	O
Hippo	B-Application
CMS	I-Application
and	O
Magnolia	B-Language
are	O
Enterprise	B-Application
Content	I-Application
Management	I-Application
systems	I-Application
built	O
on	O
the	O
JCR	O
API	B-Application
,	O
using	O
Jackrabbit	B-Language
as	O
its	O
repository	O
by	O
default	O
,	O
but	O
able	O
to	O
plug	O
in	O
any	O
other	O
JSR-170	B-Protocol
certified	O
repository	O
implementation	O
.	O
</s>
<s>
JSR-170	B-Protocol
is	O
also	O
supported	O
by	O
Oracle	B-Protocol
Beehive	I-Protocol
,	O
Oracle	O
's	O
enterprise	O
collaboration	O
software	O
.	O
</s>
<s>
Alfresco	B-Language
is	O
an	O
open	O
source	O
content	B-Protocol
management	I-Protocol
system	I-Protocol
which	O
provides	O
a	O
JCR	O
API	B-Application
onto	O
their	O
repository	O
.	O
</s>
<s>
GX	O
released	O
the	O
new	O
community	O
version	O
of	O
its	O
Web	O
enterprise	B-Application
content	I-Application
management	I-Application
(	O
ECM	O
)	O
platform	O
based	O
natively	O
on	O
Apache	B-Language
Jackrabbit	I-Language
and	O
JSR	O
.	O
</s>
<s>
PHP	O
adaptions	O
have	O
been	O
started	O
by	O
TYPO3	B-Protocol
,	O
translating	O
the	O
Java	B-Device
API	B-Application
to	O
PHP	O
.	O
</s>
<s>
The	O
PHPCR	O
interfaces	O
are	O
also	O
implemented	O
by	O
Jackalope	O
,	O
a	O
PHP	O
frontend	O
talking	O
to	O
the	O
Jackrabbit	B-Language
backend	O
through	O
the	O
WebDAV	O
interface	O
,	O
and	O
Midgard	B-Language
,	O
a	O
cross-language	O
content	B-Protocol
repository	I-Protocol
.	O
</s>
