<s>
HTTP	B-Operating_System
Switchboard	I-Operating_System
is	O
a	O
Chromium	B-Application
browser	B-Protocol
extension	I-Protocol
(	O
which	O
also	O
works	O
with	O
other	O
Chromium-based	B-Application
browsers	O
such	O
as	O
Opera	B-Application
(	O
from	O
version	O
15	O
)	O
and	O
the	O
Yandex	B-Language
browser	I-Language
)	O
that	O
allows	O
filtering	O
of	O
Hypertext	O
Transfer	O
Protocol	O
(	O
HTTP	O
)	O
requests	O
based	O
on	O
the	O
content	O
and/or	O
the	O
target	O
's	O
domain	O
name	O
.	O
</s>
<s>
It	O
comes	O
with	O
an	O
optional	O
,	O
pre-defined	O
blacklist	O
of	O
hostnames	B-Protocol
that	O
might	O
be	O
a	O
privacy	O
threat	O
when	O
sending	O
requests	O
to	O
them	O
and/or	O
a	O
security	O
threat/annoyance	O
due	O
to	O
the	O
content	O
delivered	O
in	O
the	O
response	O
.	O
</s>
<s>
HTTP	B-Operating_System
Switchboard	I-Operating_System
's	O
developer	O
,	O
Raymond	O
Hill	O
,	O
has	O
also	O
developed	O
other	O
browser	B-Protocol
extensions	I-Protocol
,	O
including	O
ad	O
filtering	O
uBlock	B-Protocol
which	O
he	O
actively	O
leads	O
as	O
uBlock	B-Protocol
Origin	I-Protocol
.	O
</s>
<s>
HTTP	B-Operating_System
Switchboard	I-Operating_System
is	O
no	O
longer	O
being	O
actively	O
developed	O
.	O
</s>
<s>
It	O
has	O
instead	O
been	O
replaced	O
by	O
uBlock	B-Protocol
Origin	I-Protocol
as	O
well	O
as	O
uMatrix	O
,	O
the	O
latter	O
being	O
an	O
as-of-now	O
unmaintained	O
extension	O
aimed	O
at	O
more	O
advanced	O
users	O
.	O
</s>
