<s>
Fluff	B-Operating_System
Busting	I-Operating_System
Purity	I-Operating_System
,	O
or	O
FB	B-Operating_System
Purity	I-Operating_System
for	O
short	O
(	O
previously	O
known	O
as	O
Facebook	B-Operating_System
Purity	I-Operating_System
)	O
is	O
a	O
web	B-Protocol
browser	I-Protocol
extension	I-Protocol
designed	O
to	O
customize	O
the	B-Application
Facebook	I-Application
website	O
's	O
user	B-Application
interface	I-Application
and	O
add	O
extra	O
functionality	O
.	O
</s>
<s>
Developed	O
by	O
Steve	O
Fernandez	O
,	O
a	O
UK-based	O
programmer	O
,	O
it	O
was	O
first	O
released	O
in	O
2009	O
as	O
a	O
Greasemonkey	B-Operating_System
script	I-Operating_System
,	O
as	O
donationware	B-License
.	O
</s>
<s>
It	O
is	O
available	O
for	O
Firefox	B-Application
,	O
Google	B-Application
Chrome	I-Application
,	O
Microsoft	B-Application
Edge	I-Application
,	O
Safari	O
,	O
Opera	B-Application
,	O
Brave	B-Application
and	O
Maxthon	B-Application
.	O
</s>
<s>
In	O
February	O
2012	O
,	O
Fernandez	O
was	O
banned	O
from	O
Facebook	B-Application
,	O
although	O
he	O
was	O
allowed	O
back	O
two	O
weeks	O
later	O
.	O
</s>
<s>
In	O
April	O
,	O
Facebook	B-Application
blocked	O
links	O
to	O
his	O
site	O
,	O
with	O
an	O
error	O
message	O
saying	O
the	O
site	O
was	O
"	O
spammy	O
or	O
abusive	O
"	O
,	O
a	O
generic	O
error	O
message	O
given	O
for	O
any	O
site	O
that	O
they	O
deem	O
to	O
have	O
violated	O
their	O
terms	O
and	O
conditions	O
for	O
any	O
reason	O
.	O
</s>
<s>
Facebook	B-Application
stopped	O
blocking	O
the	O
link	O
to	O
the	O
FB	B-Operating_System
Purity	I-Operating_System
website	O
at	O
some	O
point	O
in	O
2021	O
,	O
the	O
exact	O
date	O
unknown	O
.	O
</s>
<s>
In	O
December	O
2012	O
,	O
the	O
company	O
both	O
objected	O
to	O
the	O
name	O
"	O
Facebook	B-Operating_System
Purity	I-Operating_System
"	O
(	O
which	O
Fernandez	O
changed	O
to	O
'	O
Fluff	B-Operating_System
Busting	I-Operating_System
Purity	I-Operating_System
 '	O
in	O
response	O
)	O
,	O
and	O
claimed	O
that	O
its	O
development	O
violates	O
the	O
site	O
's	O
Terms	O
of	O
Service	O
.	O
</s>
<s>
In	O
response	O
to	O
this	O
perceived	O
violation	O
,	O
the	O
company	O
told	O
Fernandez	O
he	O
was	O
unauthorized	O
to	O
access	O
Facebook	B-Application
,	O
which	O
he	O
described	O
at	O
the	O
time	O
as	O
potentially	O
the	O
"	O
end	O
of	O
the	O
road	O
"	O
for	O
the	O
script	O
's	O
development	O
.	O
</s>
<s>
However	O
,	O
the	O
add-on	B-Operating_System
continues	O
to	O
be	O
maintained	O
and	O
updated	O
by	O
the	O
author	O
,	O
which	O
is	O
clear	O
from	O
the	O
regular	O
version	O
releases	O
on	O
the	O
FB	B-Operating_System
Purity	I-Operating_System
website	O
,	O
and	O
other	O
official	O
browser-specific	O
download	O
pages	O
of	O
the	O
FB	B-Operating_System
Purity	I-Operating_System
extension	O
:	O
(	O
Firefox	B-Application
,	O
Google	B-Application
Chrome	I-Application
,	O
Microsoft	B-Application
Edge	I-Application
,	O
Opera	B-Application
)	O
.	O
</s>
<s>
During	O
the	O
summer	O
of	O
2020	O
,	O
Facebook	B-Application
informed	O
users	O
that	O
a	O
new	O
user	B-Application
interface	I-Application
featuring	O
light	O
and	O
dark	O
views	O
would	O
become	O
mandatory	O
,	O
with	O
users	O
temporarily	O
being	O
able	O
to	O
switch	O
back	O
to	O
the	O
Classic	O
look	O
.	O
</s>
