<s>
Advogato	B-Protocol
was	O
an	O
online	B-Architecture
community	I-Architecture
and	O
social	O
networking	O
site	O
dedicated	O
to	O
free	B-Application
software	I-Application
development	I-Application
and	O
created	O
by	O
Raph	O
Levien	O
.	O
</s>
<s>
Advogato	B-Protocol
described	O
itself	O
as	O
"	O
the	O
free	B-Application
software	I-Application
developer	O
's	O
advocate.	O
"	O
</s>
<s>
Advogato	B-Protocol
was	O
an	O
early	O
pioneer	O
of	O
blogs	O
,	O
formerly	O
known	O
as	O
"	O
online	O
diaries	O
"	O
,	O
and	O
one	O
of	O
the	O
earliest	O
social	O
networking	O
websites	O
.	O
</s>
<s>
Advogato	B-Protocol
combined	O
the	O
most	O
recent	O
entries	O
from	O
each	O
user	O
's	O
diary	O
together	O
into	O
a	O
single	O
continuous	O
feed	O
called	O
the	O
recentlog	O
,	O
directly	O
inspiring	O
the	O
creation	O
of	O
the	O
Planet	B-Application
aggregator	I-Application
somewhat	O
later	O
.	O
</s>
<s>
Several	O
high-profile	O
members	O
of	O
the	O
free	B-Application
software	I-Application
and	O
open	B-Application
source	I-Application
software	I-Application
movements	O
were	O
users	O
of	O
the	O
site	O
,	O
including	O
Richard	O
M	O
.	O
Stallman	O
,	O
Eric	O
Raymond	O
,	O
Alan	O
Cox	O
,	O
Bruce	O
Perens	O
,	O
and	O
Jamie	B-Operating_System
Zawinski	I-Operating_System
.	O
</s>
<s>
Because	O
Advogato	B-Protocol
was	O
the	O
first	O
website	O
to	O
use	O
a	O
robust	O
,	O
attack-resistant	O
trust	O
metric	O
and	O
to	O
release	O
the	O
underlying	O
code	O
for	O
that	O
trust	O
mechanism	O
under	O
a	O
free	B-Application
software	I-Application
license	O
,	O
it	O
has	O
been	O
the	O
basis	O
of	O
numerous	O
research	O
papers	O
on	O
trust	O
metrics	O
and	O
social	O
networking	O
(	O
see	O
the	O
list	O
below	O
for	O
specific	O
examples	O
)	O
.	O
</s>
<s>
Advogato	B-Protocol
's	O
early	O
adoption	O
of	O
an	O
XML-RPC	B-Protocol
interface	O
led	O
to	O
its	O
use	O
as	O
an	O
example	O
of	O
how	O
such	O
interfaces	O
could	O
be	O
used	O
by	O
web	O
programmers	O
.	O
</s>
<s>
Advogato	B-Protocol
saw	O
use	O
as	O
a	O
testbed	O
for	O
social	O
networking	O
and	O
semantic	O
web	O
technologies	O
.	O
</s>
<s>
Tim	O
Berners-Lee	O
,	O
who	O
was	O
an	O
Advogato	B-Protocol
user	O
himself	O
,	O
included	O
Advogato	B-Protocol
in	O
a	O
short	O
list	O
of	O
sites	O
notable	O
for	O
their	O
early	O
adoption	O
of	O
the	O
FOAF	O
as	O
a	O
method	O
of	O
exporting	O
user	O
RDF	O
URIs	O
.	O
</s>
<s>
The	O
motivating	O
idea	O
for	O
Advogato	B-Protocol
was	O
to	O
try	O
out	O
in	O
practice	O
Levien	O
's	O
ideas	O
about	O
attack-resistant	O
trust	O
metrics	O
,	O
having	O
users	O
certify	O
each	O
other	O
in	O
a	O
kind	O
of	O
peer	O
review	O
process	O
and	O
use	O
this	O
information	O
to	O
avoid	O
the	O
abuses	O
that	O
plague	O
open	O
community	B-Architecture
sites	I-Architecture
.	O
</s>
<s>
Levien	O
observed	O
that	O
his	O
notion	O
of	O
attack-resistant	O
trust	O
metric	O
was	O
fundamentally	O
very	O
similar	O
to	O
the	O
PageRank	B-Algorithm
algorithm	I-Algorithm
used	O
by	O
Google	B-Application
to	O
rate	O
article	O
interest	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
Advogato	B-Protocol
,	O
the	O
trust	O
metric	O
was	O
designed	O
to	O
include	O
all	O
individuals	O
who	O
could	O
reasonably	O
be	O
considered	O
members	O
of	O
the	O
Free	B-Application
Software	I-Application
and	O
Open	O
Source	O
communities	O
while	O
excluding	O
others	O
.	O
</s>
<s>
The	O
implementation	O
of	O
this	O
trust	O
metric	O
was	O
through	O
an	O
Apache	B-Application
module	I-Application
called	O
mod	O
virgule	O
.	O
</s>
<s>
mod_virgule	O
is	O
free	B-Application
software	I-Application
,	O
licensed	O
under	O
the	O
GPL	B-License
and	O
written	O
in	O
C	B-Language
.	O
</s>
<s>
Despite	O
the	O
trust	O
metric	O
,	O
posting	O
privileges	O
to	O
the	O
front	O
page	O
of	O
Advogato	B-Protocol
were	O
gained	O
by	O
controversial	O
individuals	O
,	O
leading	O
some	O
to	O
claim	O
Advogato	B-Protocol
's	O
trust	O
metric	O
solution	O
was	O
faulty	O
.	O
</s>
<s>
Misunderstanding	O
of	O
the	O
purpose	O
of	O
Advogato	B-Protocol
's	O
trust	O
metric	O
was	O
common	O
,	O
which	O
often	O
led	O
to	O
the	O
assumption	O
that	O
it	O
should	O
exclude	O
specific	O
individuals	O
on	O
the	O
basis	O
that	O
they	O
were	O
known	O
cranks	O
.	O
</s>
