<s>
NorduGrid	B-Operating_System
is	O
a	O
collaboration	O
aiming	O
at	O
development	O
,	O
maintenance	O
and	O
support	O
of	O
the	O
free	O
Grid	B-Architecture
middleware	B-General_Concept
,	O
known	O
as	O
the	O
Advanced	B-Operating_System
Resource	I-Operating_System
Connector	I-Operating_System
(	O
ARC	B-Operating_System
)	O
.	O
</s>
<s>
The	O
name	O
NorduGrid	B-Operating_System
first	O
became	O
known	O
in	O
2001	O
as	O
short	O
for	O
the	O
project	O
called	O
"	O
Nordic	O
Testbed	O
for	O
Wide	O
Area	O
Computing	O
and	O
Data	O
Handling	O
"	O
funded	O
by	O
the	O
Nordic	O
Council	O
of	O
Ministers	O
via	O
the	O
Nordunet2	O
programme	O
.	O
</s>
<s>
Following	O
evaluation	O
of	O
the	O
then	O
existing	O
Grid	B-Architecture
technology	O
solutions	O
,	O
NorduGrid	B-Operating_System
developers	O
came	O
up	O
with	O
an	O
alternative	O
software	B-Architecture
architecture	I-Architecture
.	O
</s>
<s>
It	O
was	O
implemented	O
and	O
demonstrated	O
in	O
May	O
2002	O
,	O
and	O
soon	O
became	O
known	O
as	O
the	O
NorduGrid	B-Operating_System
Middleware	B-General_Concept
.	O
</s>
<s>
In	O
2004	O
this	O
middleware	B-General_Concept
solution	O
was	O
given	O
a	O
proper	O
name	O
,	O
the	O
Advanced	B-Operating_System
Resource	I-Operating_System
Connector	I-Operating_System
(	O
ARC	B-Operating_System
)	O
.	O
</s>
<s>
Until	O
May	O
2003	O
,	O
NorduGrid	B-Operating_System
headquarters	O
were	O
in	O
the	O
Niels	O
Bohr	O
Institute	O
;	O
at	O
the	O
5th	O
NorduGrid	B-Operating_System
Workshop	O
it	O
was	O
decided	O
to	O
move	O
them	O
to	O
the	O
Oslo	O
University	O
.	O
</s>
<s>
The	O
present-day	O
formal	O
collaboration	O
was	O
established	O
in	O
2005	O
by	O
five	O
Nordic	O
academic	O
institutes	O
(	O
Niels	O
Bohr	O
Institute	O
in	O
Copenhagen	O
,	O
Denmark	O
,	O
Helsinki	O
Institute	O
of	O
Physics	O
in	O
Finland	O
,	O
Oslo	O
University	O
in	O
Norway	O
,	O
and	O
Lund	O
and	O
Uppsala	O
Universities	O
in	O
Sweden	O
)	O
with	O
the	O
goal	O
to	O
develop	O
,	O
support	O
,	O
maintain	O
and	O
popularize	O
ARC	B-Operating_System
.	O
</s>
<s>
Deployment	O
and	O
support	O
of	O
the	O
Nordic	O
Grid	B-Architecture
infrastructure	O
itself	O
became	O
the	O
responsibility	O
of	O
the	O
NDGF	O
project	O
,	O
launched	O
in	O
June	O
2006	O
.	O
</s>
<s>
This	O
marked	O
clear	O
separation	O
between	O
Grid	B-Architecture
middleware	B-General_Concept
providers	O
and	O
infrastructure	O
services	O
providers	O
.	O
</s>
<s>
To	O
further	O
support	O
ARC	B-Operating_System
development	O
,	O
NorduGrid	B-Operating_System
and	O
several	O
other	O
interested	O
partners	O
secured	O
dedicated	O
funding	O
through	O
EU	O
FP6	O
project	O
KnowARC	B-Operating_System
.	O
</s>
<s>
NorduGrid	B-Operating_System
Collaboration	O
is	O
based	O
upon	O
a	O
non-binding	O
Memorandum	O
of	O
Understanding	O
and	O
is	O
open	O
for	O
new	O
members	O
.	O
</s>
<s>
The	O
NorduGrid	B-Operating_System
Collaboration	O
is	O
the	O
consortium	O
behind	O
the	O
ARC	B-Operating_System
middleware	B-General_Concept
,	O
and	O
its	O
key	O
goal	O
is	O
to	O
ensure	O
that	O
ARC	B-Operating_System
is	O
further	O
developed	O
,	O
maintained	O
,	O
supported	O
and	O
widely	O
deployed	O
,	O
while	O
remaining	O
a	O
free	O
open-source	B-Application
software	I-Application
,	O
suitable	O
for	O
a	O
wide	O
variety	O
of	O
high-throughput	B-Operating_System
Grid	B-Architecture
computational	O
tasks	O
.	O
</s>
<s>
The	O
ultimate	O
goal	O
is	O
to	O
provide	O
a	O
reliable	O
,	O
scalable	O
,	O
portable	O
and	O
full-featured	O
solution	O
for	O
Grid	B-Architecture
infrastructures	O
,	O
conformant	O
with	O
open	O
standards	O
,	O
primarily	O
those	O
developed	O
in	O
the	O
framework	O
of	O
the	O
Open	O
Grid	B-Architecture
Forum	O
.	O
</s>
<s>
While	O
ARC	B-Operating_System
software	O
development	O
may	O
and	O
does	O
often	O
take	O
place	O
outside	O
NorduGrid	B-Operating_System
,	O
the	O
Collaboration	O
coordinates	O
contributions	O
to	O
the	O
code	O
and	O
maintains	O
the	O
code	O
and	O
software	O
repositories	O
,	O
as	O
well	O
as	O
a	O
build	O
system	O
,	O
an	O
issue	O
tracking	O
system	O
and	O
other	O
necessary	O
software	O
development	O
services	O
.	O
</s>
<s>
NorduGrid	B-Operating_System
defines	O
strategical	O
directions	O
for	O
development	O
of	O
ARC	B-Operating_System
and	O
ensures	O
financial	O
support	O
for	O
it	O
.	O
</s>
<s>
The	O
term	O
"	O
ARC	B-Operating_System
Community	O
"	O
is	O
used	O
to	O
refer	O
to	O
various	O
groups	O
of	O
people	O
willing	O
to	O
share	O
their	O
computational	O
resources	O
via	O
ARC	B-Operating_System
.	O
</s>
<s>
Contrary	O
to	O
the	O
popular	O
belief	O
,	O
NorduGrid	B-Operating_System
members	O
are	O
not	O
required	O
to	O
provide	O
computing	O
or	O
storage	O
resources	O
;	O
neither	O
offering	O
such	O
resources	O
grants	O
an	O
automatic	O
membership	O
.	O
</s>
<s>
Still	O
,	O
ARC	B-Operating_System
community	O
as	O
a	O
whole	O
owns	O
a	O
substantial	O
amount	O
of	O
computing	O
and	O
storage	O
resources	O
.	O
</s>
<s>
On	O
a	O
voluntarily	O
basis	O
,	O
and	O
for	O
the	O
purpose	O
of	O
the	O
open-source	B-Application
development	I-Application
process	O
,	O
community	O
members	O
may	O
donate	O
CPU	O
cycles	O
and	O
some	O
storage	O
space	O
to	O
the	O
developers	O
and	O
testers	O
.	O
</s>
<s>
Such	O
resources	O
constitute	O
the	O
testbed	O
for	O
the	O
ARC	B-Operating_System
middleware	B-General_Concept
.	O
</s>
<s>
Other	O
than	O
such	O
donated	O
community	O
resources	O
,	O
NorduGrid	B-Operating_System
does	O
not	O
provide	O
or	O
allocate	O
any	O
computational	O
resources	O
and	O
does	O
not	O
coordinate	O
worldwide	O
deployment	O
of	O
ARC	B-Operating_System
.	O
</s>
<s>
Actual	O
deployment	O
and	O
usage	O
of	O
ARC-based	O
distributed	O
computing	O
infrastructures	O
is	O
coordinated	O
by	O
the	O
respective	O
infrastructure	O
projects	O
,	O
such	O
as	O
e.g.	O
</s>
<s>
Apart	O
from	O
contributing	O
computational	O
resources	O
,	O
many	O
groups	O
develop	O
higher-level	O
software	O
tools	O
on	O
top	O
of	O
ARC	B-Operating_System
(	O
e.g.	O
)	O
.	O
</s>
<s>
This	O
kind	O
of	O
development	O
is	O
not	O
coordinated	O
by	O
NorduGrid	B-Operating_System
,	O
but	O
assistance	O
is	O
provided	O
by	O
the	O
Collaboration	O
upon	O
request	O
.	O
</s>
<s>
(	O
CA	O
)	O
is	O
currently	O
the	O
only	O
major	O
infrastructure	O
service	O
provided	O
by	O
the	O
NorduGrid	B-Operating_System
.	O
</s>
<s>
This	O
Authority	O
issues	O
electronic	O
certificates	O
to	O
users	O
and	O
services	O
,	O
such	O
that	O
they	O
can	O
work	O
in	O
Grid	B-Architecture
environments	O
.	O
</s>
<s>
Present	O
day	O
Grid	B-Architecture
implementations	O
require	O
X.509	O
certificates	O
to	O
validate	O
identity	O
of	O
Grid	B-Architecture
participants	O
.	O
</s>
<s>
NorduGrid	B-Operating_System
CA	O
provides	O
such	O
certificates	O
to	O
individuals	O
and	O
machines	O
associated	O
with	O
research	O
and/or	O
academic	O
institutions	O
in	O
Denmark	O
,	O
Finland	O
,	O
Norway	O
and	O
Sweden	O
.	O
</s>
<s>
The	O
NorduGrid	B-Operating_System
Certification	O
Authority	O
is	O
a	O
member	O
of	O
the	O
.	O
</s>
