<s>
Vimperator	B-Operating_System
is	O
a	O
discontinued	O
Firefox	B-Operating_System
extension	I-Operating_System
forked	O
from	O
the	O
original	O
Firefox	B-Operating_System
extension	I-Operating_System
version	O
of	O
Conkeror	B-Protocol
and	O
designed	O
to	O
provide	O
a	O
more	O
efficient	O
user	O
interface	O
for	O
keyboard-fluent	O
users	O
.	O
</s>
<s>
The	O
design	O
is	O
heavily	O
inspired	O
by	O
the	O
Vim	B-Application
text	I-Application
editor	I-Application
,	O
and	O
the	O
authors	O
try	O
to	O
maintain	O
consistency	O
with	O
it	O
wherever	O
possible	O
.	O
</s>
<s>
One	O
of	O
Vimperator	B-Operating_System
's	O
most	O
notable	O
features	O
is	O
mouseless	O
browsing	O
,	O
which	O
is	O
a	O
result	O
of	O
Vimperator	B-Operating_System
's	O
hints	O
,	O
command	B-Application
line	I-Application
with	O
command	O
completion	O
,	O
and	O
comprehensive	O
keyboard-accessible	O
help	O
system	O
.	O
</s>
<s>
Vimperator	B-Operating_System
hints	O
allow	O
users	O
to	O
perform	O
actions	O
on	O
clickable	O
web	O
page	O
items	O
that	O
would	O
normally	O
be	O
completed	O
with	O
the	O
mouse	O
.	O
</s>
<s>
This	O
function	O
was	O
originated	O
in	O
an	O
extension	O
named	O
Hit-a-Hint	O
,	O
and	O
the	O
vimperator	B-Operating_System
developers	O
adopted	O
the	O
function	O
as	O
a	O
vimperator	B-Operating_System
module	O
in	O
the	O
early	O
stage	O
of	O
development	O
,	O
and	O
rewrote	O
the	O
code	O
to	O
make	O
it	O
lighter	O
in	O
pages	O
with	O
many	O
links	O
.	O
</s>
<s>
Most	O
of	O
Vimperator	B-Operating_System
's	O
features	O
may	O
be	O
accessed	O
via	O
its	O
Vim-like	O
command	B-Application
line	I-Application
that	O
appears	O
at	O
the	O
bottom	O
of	O
each	O
window	O
.	O
</s>
<s>
As	O
with	O
Vim	B-Application
,	O
these	O
commands	O
begin	O
with	O
'	O
:	O
'	O
.	O
</s>
<s>
When	O
the	O
'	O
:	O
'	O
key	O
is	O
pressed	O
,	O
Vimperator	B-Operating_System
moves	O
into	O
"	O
ex	B-Device
mode	I-Device
,	O
"	O
which	O
moves	O
the	O
cursor	O
into	O
the	O
command	B-Application
line	I-Application
for	O
the	O
user	O
to	O
complete	O
the	O
command	O
.	O
</s>
<s>
Vimperator	B-Operating_System
provides	O
a	O
sophisticated	O
completion	O
system	O
with	O
auto-completion	O
support	O
.	O
</s>
<s>
This	O
not	O
only	O
saves	O
typing	O
,	O
but	O
allows	O
the	O
user	O
to	O
explore	O
without	O
having	O
to	O
resort	O
to	O
manuals	O
,	O
or	O
indeed	O
leave	O
the	O
command	B-Application
line	I-Application
at	O
all	O
.	O
</s>
<s>
For	O
instance	O
,	O
instead	O
of	O
using	O
the	O
tab	O
menu	O
,	O
a	O
user	O
with	O
auto-completion	O
enabled	O
may	O
press	O
'	O
b	O
 '	O
to	O
open	O
the	O
command	B-Application
line	I-Application
to	O
the	O
'	O
buffer	O
 '	O
command	O
,	O
which	O
will	O
automatically	O
provide	O
a	O
completion	O
list	O
of	O
all	O
open	O
tabs	O
.	O
</s>
<s>
To	O
ameliorate	O
its	O
steep	O
learning	O
curve	O
,	O
Vimperator	B-Operating_System
provides	O
an	O
online	O
help	O
system	O
similar	O
to	O
that	O
of	O
Vim	B-Application
.	O
</s>
<s>
Vimperator	B-Operating_System
allows	O
the	O
use	O
of	O
external	O
texteditors	O
for	O
data	O
entry	O
in	O
text	O
input	O
areas	O
.	O
</s>
<s>
Vimperator	B-Operating_System
supports	O
extending	O
its	O
base	O
functionality	O
with	O
scripts	O
.	O
</s>
<s>
The	O
scripts	O
are	O
written	O
using	O
JavaScript	B-Language
and	O
a	O
limited	O
version	O
of	O
Vimscript	O
.	O
</s>
