<s>
PrimeGrid	B-Operating_System
is	O
a	O
volunteer	O
computing	O
project	O
that	O
searches	O
for	O
very	O
large	O
(	O
up	O
to	O
world-record	O
size	O
)	O
prime	O
numbers	O
whilst	O
also	O
aiming	O
to	O
solve	O
long-standing	O
mathematical	O
conjectures	O
.	O
</s>
<s>
It	O
uses	O
the	O
Berkeley	B-Operating_System
Open	I-Operating_System
Infrastructure	I-Operating_System
for	I-Operating_System
Network	I-Operating_System
Computing	I-Operating_System
(	O
BOINC	B-Operating_System
)	O
platform	O
.	O
</s>
<s>
PrimeGrid	B-Operating_System
offers	O
a	O
number	O
of	O
subprojects	O
for	O
prime-number	O
sieving	O
and	O
discovery	O
.	O
</s>
<s>
Some	O
of	O
these	O
are	O
available	O
through	O
the	O
BOINC	B-Operating_System
client	O
,	O
others	O
through	O
the	O
PRPNet	O
client	O
.	O
</s>
<s>
Different	O
subprojects	O
may	O
run	O
on	O
different	O
operating	O
systems	O
,	O
and	O
may	O
have	O
executables	O
for	O
CPUs	O
,	O
GPUs	O
,	O
or	O
both	O
;	O
while	O
running	O
the	O
Lucas	B-Algorithm
–	I-Algorithm
Lehmer	I-Algorithm
–	I-Algorithm
Riesel	I-Algorithm
test	I-Algorithm
,	O
CPUs	O
with	O
Advanced	B-General_Concept
Vector	I-General_Concept
Extensions	I-General_Concept
and	O
Fused	B-General_Concept
Multiply-Add	I-General_Concept
instruction	O
sets	O
will	O
yield	O
the	O
fastest	O
results	O
for	O
non-GPU	O
accelerated	O
workloads	O
.	O
</s>
<s>
PrimeGrid	B-Operating_System
awards	O
badges	O
to	O
users	O
in	O
recognition	O
of	O
achieving	O
certain	O
defined	O
levels	O
of	O
credit	O
for	O
work	O
done	O
.	O
</s>
<s>
The	O
issuing	O
of	O
badges	O
should	O
also	O
benefit	O
PrimeGrid	B-Operating_System
by	O
evening	O
out	O
the	O
participation	O
in	O
the	O
less	O
popular	O
sub	O
projects	O
.	O
</s>
<s>
PrimeGrid	B-Operating_System
started	O
in	O
June	O
2005	O
under	O
the	O
name	O
Message	O
@home	O
and	O
tried	O
to	O
decipher	O
text	O
fragments	O
hashed	O
with	O
MD5	B-Algorithm
.	O
</s>
<s>
Message	O
@home	O
was	O
a	O
test	O
to	O
port	O
the	O
BOINC	B-Operating_System
scheduler	O
to	O
Perl	O
to	O
obtain	O
greater	O
portability	O
.	O
</s>
<s>
With	O
the	O
chance	O
to	O
succeed	O
too	O
small	O
,	O
it	O
discarded	O
the	O
RSA	O
challenges	O
,	O
was	O
renamed	O
to	O
PrimeGrid	B-Operating_System
,	O
and	O
started	O
generating	O
a	O
list	O
of	O
the	O
first	O
prime	O
numbers	O
.	O
</s>
<s>
In	O
June	O
2006	O
,	O
dialog	O
started	O
with	O
Riesel	B-Operating_System
Sieve	I-Operating_System
to	O
bring	O
their	O
project	O
to	O
the	O
BOINC	B-Operating_System
community	O
.	O
</s>
<s>
PrimeGrid	B-Operating_System
provided	O
PerlBOINC	O
support	O
and	O
Riesel	B-Operating_System
Sieve	I-Operating_System
was	O
successful	O
in	O
implementing	O
their	O
sieve	O
as	O
well	O
as	O
a	O
prime	O
finding	O
(	O
LLR	B-Algorithm
)	O
application	O
.	O
</s>
<s>
With	O
collaboration	O
from	O
Riesel	B-Operating_System
Sieve	I-Operating_System
,	O
PrimeGrid	B-Operating_System
was	O
able	O
to	O
implement	O
the	O
LLR	B-Algorithm
application	O
in	O
partnership	O
with	O
another	O
prime	O
finding	O
project	O
,	O
Twin	B-Operating_System
Prime	I-Operating_System
Search	I-Operating_System
(	O
TPS	O
)	O
.	O
</s>
<s>
In	O
November	O
2006	O
,	O
the	O
TPS	O
LLR	B-Algorithm
application	O
was	O
officially	O
released	O
at	O
PrimeGrid	B-Operating_System
.	O
</s>
<s>
In	O
the	O
fall	O
of	O
the	O
same	O
year	O
,	O
PrimeGrid	B-Operating_System
migrated	O
its	O
systems	O
from	O
PerlBOINC	O
to	O
standard	O
BOINC	B-Operating_System
software	O
.	O
</s>
<s>
Since	O
September	O
2008	O
,	O
PrimeGrid	B-Operating_System
is	O
also	O
running	O
a	O
Proth	O
prime	O
sieving	O
subproject	O
.	O
</s>
<s>
,	O
PrimeGrid	B-Operating_System
is	O
working	O
on	O
or	O
has	O
worked	O
on	O
the	O
following	O
projects	O
:	O
</s>
<s>
Active	O
LLR	B-Algorithm
project	O
?	O
</s>
<s>
PrimeGrid	B-Operating_System
added	O
the	O
+1	O
form	O
and	O
continues	O
the	O
search	O
up	O
ton	O
=	O
25M	O
.	O
</s>
<s>
One	O
of	O
PrimeGrid	B-Operating_System
projects	O
was	O
AP26	O
Search	O
which	O
searched	O
for	O
a	O
record	O
26	O
primes	O
in	O
arithmetic	O
progression	O
.	O
</s>
<s>
PrimeGrid	B-Operating_System
is	O
also	O
running	O
a	O
search	O
for	O
Cullen	O
prime	O
numbers	O
,	O
yielding	O
the	O
two	O
largest	O
known	O
Cullen	O
primes	O
.	O
</s>
<s>
The	O
first	O
one	O
being	O
the	O
14th	O
largest	O
known	O
prime	O
at	O
the	O
time	O
of	O
discovery	O
,	O
and	O
the	O
second	O
one	O
was	O
PrimeGrid	B-Operating_System
's	O
largest	O
prime	O
found	O
at	O
over	O
2	O
million	O
digits	O
.	O
</s>
<s>
On	O
24	O
September	O
2022	O
,	O
PrimeGrid	B-Operating_System
discovered	O
the	O
largest	O
known	O
Generalized	O
Fermat	O
prime	O
to	O
date	O
,	O
.	O
</s>
<s>
Primegrid	B-Operating_System
worked	O
with	O
the	O
Twin	B-Operating_System
Prime	I-Operating_System
Search	I-Operating_System
to	O
search	O
for	O
a	O
record-sized	O
twin	O
prime	O
at	O
approximately	O
58,700	O
digits	O
.	O
</s>
<s>
The	O
new	O
world	O
's	O
largest	O
known	O
twin	O
prime	O
was	O
eventually	O
discovered	O
on	O
January	O
15	O
,	O
2007	O
(	O
sieved	O
by	O
Twin	B-Operating_System
Prime	I-Operating_System
Search	I-Operating_System
and	O
tested	O
by	O
PrimeGrid	B-Operating_System
)	O
.	O
</s>
<s>
It	O
was	O
completed	O
in	O
August	O
2009	O
when	O
Primegrid	B-Operating_System
found	O
.	O
</s>
<s>
PrimeGrid	B-Operating_System
also	O
found	O
the	O
largest	O
known	O
generalized	O
Woodall	O
prime	O
,	O
</s>
<s>
PrimeGrid	B-Operating_System
's	O
author	O
Rytis	O
Slatkevičius	O
has	O
been	O
featured	O
as	O
a	O
young	O
entrepreneur	O
in	O
The	O
Economist	O
.	O
</s>
<s>
PrimeGrid	B-Operating_System
has	O
also	O
been	O
featured	O
in	O
an	O
article	O
by	O
Francois	O
Grey	O
in	O
the	O
CERN	O
Courier	O
and	O
a	O
talk	O
about	O
citizen	O
cyberscience	O
in	O
TEDx	O
Warwick	O
conference	O
.	O
</s>
<s>
In	O
the	O
first	O
Citizen	O
Cyberscience	O
Summit	O
,	O
Rytis	O
Slatkevičius	O
gave	O
a	O
talk	O
as	O
a	O
founder	O
of	O
PrimeGrid	B-Operating_System
,	O
named	O
Finding	O
primes	O
:	O
from	O
digits	O
to	O
digital	O
technology	O
,	O
</s>
