<s>
Advanced	B-Operating_System
Resource	I-Operating_System
Connector	I-Operating_System
(	O
ARC	O
)	O
is	O
a	O
grid	B-Architecture
computing	I-Architecture
middleware	B-General_Concept
introduced	O
by	O
NorduGrid	B-Operating_System
.	O
</s>
<s>
It	O
provides	O
a	O
common	O
interface	O
for	O
submission	O
of	O
computational	O
tasks	O
to	O
different	O
distributed	B-Architecture
computing	I-Architecture
systems	O
and	O
thus	O
can	O
enable	O
grid	O
infrastructures	O
of	O
varying	O
size	O
and	O
complexity	O
.	O
</s>
<s>
ARC-CE	O
functionality	O
includes	O
data	O
staging	O
and	O
caching	O
,	O
developed	O
in	O
order	O
to	O
support	O
data-intensive	O
distributed	B-Architecture
computing	I-Architecture
.	O
</s>
<s>
ARC	O
is	O
an	O
open	B-Application
source	I-Application
software	I-Application
distributed	O
under	O
the	O
Apache	B-Application
License	I-Application
2.0	O
.	O
</s>
<s>
ARC	O
appeared	O
(	O
and	O
is	O
still	O
often	O
referred	O
to	O
)	O
as	O
the	O
NorduGrid	B-Operating_System
middleware	B-General_Concept
,	O
originally	O
proposed	O
as	O
an	O
architecture	O
on	O
top	O
of	O
the	O
Globus	O
Toolkit	O
optimized	O
for	O
the	O
needs	O
of	O
High-Energy	O
Physics	O
computing	O
for	O
the	O
Large	O
Hadron	O
Collider	O
experiments	O
.	O
</s>
<s>
First	O
deployment	O
of	O
ARC	O
at	O
the	O
NorduGrid	B-Operating_System
testbed	O
took	O
place	O
in	O
summer	O
2002	O
,	O
and	O
by	O
2003	O
it	O
was	O
used	O
to	O
support	O
complex	O
computations	O
.	O
</s>
<s>
The	O
first	O
stable	O
release	O
of	O
ARC	O
(	O
version	O
0.4	O
)	O
came	O
out	O
in	O
April	O
2004	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
<s>
The	O
name	O
"	O
Advanced	B-Operating_System
Resource	I-Operating_System
Connector	I-Operating_System
"	O
was	O
introduced	O
for	O
this	O
release	O
to	O
distinguish	O
the	O
middleware	B-General_Concept
from	O
the	O
infrastructure	O
.	O
</s>
<s>
In	O
2005	O
,	O
NorduGrid	B-Operating_System
was	O
formally	O
established	O
as	O
a	O
collaboration	O
to	O
support	O
and	O
coordinate	O
ARC	O
development	O
.	O
</s>
<s>
In	O
2006	O
two	O
closely	O
related	O
projects	O
were	O
launched	O
:	O
the	O
Nordic	O
Data	O
Grid	O
Facility	O
,	O
deploying	O
a	O
pan-Nordic	O
e-Science	O
infrastructure	O
based	O
on	O
ARC	O
,	O
and	O
KnowARC	B-Operating_System
,	O
focused	O
on	O
transforming	O
ARC	O
into	O
a	O
next	O
generation	O
Grid	O
middleware	B-General_Concept
.	O
</s>
<s>
Later	O
that	O
year	O
,	O
the	O
first	O
technology	O
preview	O
of	O
the	O
next	O
generation	O
ARC	O
middleware	B-General_Concept
was	O
made	O
available	O
,	O
though	O
was	O
not	O
distributed	O
with	O
ARC	O
itself	O
.	O
</s>
<s>
In	O
2008	O
,	O
the	O
NorduGrid	B-Operating_System
consortium	O
adopted	O
the	O
Apache	B-Application
License	I-Application
for	O
all	O
ARC	O
components	O
.	O
</s>
<s>
In	O
parallel	O
to	O
ARC	O
v0.8	O
,	O
the	O
EU	O
KnowARC	B-Operating_System
project	O
released	O
in	O
November	O
2009	O
the	O
conceptual	O
ARC	O
NOX	O
suite	O
,	O
which	O
was	O
a	O
complete	O
Grid	O
solution	O
,	O
fully	O
based	O
on	O
Web	O
service	O
technologies	O
.	O
</s>
<s>
In	O
May	O
2011	O
,	O
NorduGrid	B-Operating_System
released	O
ARC	O
v11.05	O
(	O
adopting	O
Ubuntu	O
versioning	O
scheme	O
this	O
time	O
)	O
.	O
</s>
<s>
ARC	O
is	O
free	O
software	O
available	O
from	O
the	O
NorduGrid	B-Operating_System
public	O
repository	O
,	O
both	O
as	O
binary	O
packages	O
for	O
a	O
variety	O
of	O
Linux	B-Application
systems	O
and	O
source	O
,	O
as	O
well	O
as	O
on	O
GitHub	O
.	O
</s>
<s>
The	O
open	B-Application
source	I-Application
development	O
of	O
the	O
ARC	O
middleware	B-General_Concept
is	O
coordinated	O
by	O
the	O
NorduGrid	B-Operating_System
collaboration	O
.	O
</s>
<s>
Contributions	O
to	O
the	O
software	O
,	O
documentation	O
and	O
dissemination	O
activities	O
are	O
coming	O
from	O
the	O
community	O
and	O
from	O
various	O
projects	O
,	O
such	O
as	O
the	O
EU	O
KnowARC	B-Operating_System
and	O
EMI	O
projects	O
,	O
NDGF	O
,	O
NeIC	O
and	O
various	O
national	O
infrastructure	O
and	O
research	O
projects	O
.	O
</s>
<s>
In	O
2010-2013	O
,	O
several	O
key	O
ARC	O
components	O
-	O
most	O
notably	O
,	O
HED	O
,	O
A-REX	O
,	O
clients	O
and	O
libraries	O
-	O
were	O
included	O
in	O
the	O
European	B-Operating_System
Middleware	I-Operating_System
Initiative	I-Operating_System
(	O
EMI	O
)	O
software	O
stack	O
.	O
</s>
<s>
Through	O
EMI	O
,	O
ARC	O
became	O
a	O
part	O
of	O
the	O
Unified	O
Middleware	B-General_Concept
Distribution	O
(	O
UMD	O
)	O
of	O
the	O
European	O
Grid	O
Infrastructure	O
(	O
EGI	O
)	O
.	O
</s>
<s>
Grid-enabled	O
Know-how	O
Sharing	O
Technology	O
Based	O
on	O
ARC	O
Services	O
and	O
Open	O
Standards	O
(	O
KnowARC	B-Operating_System
)	O
was	O
a	O
Sixth	O
Framework	O
Programme	O
Specific	O
Targeted	O
Research	O
Project	O
,	O
funded	O
under	O
Priority	O
IST-2005-2.5.4	O
"	O
Advanced	O
Grid	O
Technologies	O
,	O
Systems	O
and	O
Services	O
"	O
from	O
June	O
2006	O
to	O
November	O
2009	O
.	O
</s>
<s>
In	O
July	O
2009	O
,	O
KnowARC	B-Operating_System
announced	O
it	O
contributed	O
to	O
the	O
integration	O
of	O
Grid	O
technologies	O
into	O
official	O
Linux	B-Application
repositories	O
by	O
adding	O
Globus	O
Toolkit	O
components	O
into	O
Fedora	O
and	O
Debian	O
repositories	O
.	O
</s>
