<s>
A	O
userscript	B-Language
(	O
or	O
user	B-Language
script	I-Language
)	O
is	O
a	O
program	O
,	O
usually	O
written	O
in	O
JavaScript	B-Language
,	O
for	O
modifying	O
web	O
pages	O
to	O
augment	B-Protocol
browsing	I-Protocol
.	O
</s>
<s>
Uses	O
include	O
adding	O
shortcut	O
buttons	O
and	O
keyboard	O
shortcuts	O
,	O
controlling	O
playback	O
speeds	O
,	O
adding	O
features	O
to	O
sites	O
,	O
and	O
enhancing	O
the	O
browsing	B-Protocol
history	I-Protocol
.	O
</s>
<s>
On	O
desktop	O
browsers	O
such	O
as	O
Firefox	O
,	O
userscripts	B-Language
are	O
enabled	O
by	O
use	O
of	O
a	O
userscript	B-Language
manager	I-Language
browser	B-Protocol
extension	I-Protocol
such	O
as	O
Greasemonkey	B-Operating_System
.	O
</s>
<s>
The	O
Presto-based	O
Opera-supported	O
userscripts	B-Language
(	O
referred	O
to	O
as	O
User	O
JavaScript	B-Language
)	O
are	O
placed	O
in	O
a	O
designated	O
directory	O
.	O
</s>
<s>
Userscripts	B-Language
are	O
often	O
referred	O
to	O
as	O
Greasemonkey	B-Operating_System
scripts	O
,	O
named	O
after	O
the	O
original	O
userscript	B-Language
manager	I-Language
for	O
Firefox	O
.	O
</s>
<s>
On	O
Wikipedia	O
,	O
a	O
user	B-Language
scripts	I-Language
feature	O
is	O
enabled	O
for	O
registered	O
users	O
that	O
allows	O
them	O
to	O
install	O
userscripts	B-Language
to	O
augment	O
editing	O
and	O
viewing	O
of	O
the	O
encyclopedia	O
's	O
pages	O
.	O
</s>
<s>
A	O
userscript	B-Language
manager	I-Language
is	O
a	O
type	O
of	O
browser	B-Protocol
extension	I-Protocol
and	O
augmented	B-Protocol
browsing	I-Protocol
technology	O
that	O
provides	O
a	O
user	O
interface	O
to	O
manage	O
scripts	O
.	O
</s>
<s>
The	O
main	O
purpose	O
of	O
a	O
userscript	B-Language
manager	I-Language
is	O
to	O
execute	O
scripts	O
on	O
webpages	O
as	O
they	O
are	O
loaded	O
.	O
</s>
<s>
The	O
most	O
common	O
operations	O
performed	O
by	O
a	O
userscript	B-Language
manager	I-Language
include	O
downloading	O
,	O
creating	O
,	O
installing	O
,	O
organizing	O
,	O
deleting	O
and	O
editing	O
scripts	O
,	O
as	O
well	O
as	O
modifying	O
script	O
permissions	O
(	O
e.g.	O
</s>
<s>
One	O
aspect	O
of	O
userscripts	B-Language
is	O
that	O
they	O
can	O
be	O
shared	O
.	O
</s>
<s>
They	O
can	O
be	O
uploaded	O
to	O
a	O
userscript	B-Language
repository	O
where	O
they	O
become	O
available	O
to	O
other	O
users	O
for	O
downloading	O
.	O
</s>
<s>
Historically	O
(	O
circa	O
2005	O
–	O
2011	O
)	O
userscripts.org,	O
created	O
by	O
American	O
programmer	O
Jesse	O
Andrews	O
,	O
was	O
the	O
largest	O
such	O
repository	O
for	O
userscripts	B-Language
.	O
</s>
<s>
A	O
handful	O
of	O
the	O
most	O
active	O
contributors	O
in	O
the	O
userscripts.org	O
community	O
created	O
OpenUserJS	O
,	O
which	O
is	O
actively	O
in	O
use	O
today	O
.	O
</s>
<s>
Users	O
of	O
the	O
Greasemonkey	B-Operating_System
and	O
Tampermonkey	B-Operating_System
extensions	O
may	O
choose	O
to	O
install	O
scripts	O
from	O
any	O
location	O
.	O
</s>
