<s>
Operator	O
was	O
an	O
extension	O
for	O
the	O
Mozilla	B-Application
Firefox	I-Application
web	O
browser	O
.	O
</s>
<s>
It	O
parses	B-Language
and	O
acts	O
upon	O
a	O
number	O
of	O
microformats	B-General_Concept
,	O
as	O
well	O
as	O
validating	O
them	O
.	O
</s>
<s>
Operator	O
lets	O
the	O
user	O
access	O
microformats	B-General_Concept
through	O
a	O
number	O
of	O
methods	O
,	O
all	O
of	O
which	O
are	O
optional	O
:	O
a	O
toolbar	O
,	O
a	O
toolbar	O
button	O
,	O
a	O
status	O
bar	O
icon	O
,	O
a	O
location	O
bar	O
icon	O
,	O
or	O
a	O
sidebar	O
.	O
</s>
<s>
It	O
has	O
native	O
support	O
for	O
several	O
microformats	B-General_Concept
:	O
</s>
<s>
and	O
is	O
extensible	O
,	O
in	O
that	O
users	O
can	O
add	O
new	O
actions	O
for	O
the	O
included	O
microformats	B-General_Concept
,	O
or	O
specify	O
additional	O
microformat	B-General_Concept
recognition	O
.	O
</s>
<s>
It	O
forms	O
the	O
basis	O
for	O
Firefox	B-Application
3	O
's	O
microformats	B-General_Concept
API	O
,	O
allowing	O
native	O
support	O
,	O
but	O
has	O
no	O
direct	O
user	O
interface	O
,	O
due	O
to	O
lack	O
of	O
consensus	O
on	O
the	O
implementation	O
in	O
the	O
GUI	B-Application
.	O
</s>
