<s>
A	O
helper	B-Protocol
application	I-Protocol
is	O
an	O
external	O
viewer	O
program	O
launched	O
to	O
display	O
content	O
retrieved	O
using	O
a	O
web	B-Application
browser	I-Application
.	O
</s>
<s>
Some	O
examples	O
include	O
JPEGview	B-Application
,	O
Windows	B-Device
Media	I-Device
Player	I-Device
,	O
QuickTime	B-Application
Player	I-Application
,	O
Real	B-Application
Player	I-Application
and	O
Adobe	B-Application
Reader	I-Application
.	O
</s>
<s>
Unlike	O
a	O
plugin	B-Application
whose	O
full	O
code	O
is	O
included	O
into	O
the	O
browser	B-Application
's	O
address	B-General_Concept
space	I-General_Concept
,	O
a	O
helper	B-Protocol
application	I-Protocol
is	O
a	O
standard	O
application	O
,	O
typically	O
an	O
image	B-Application
viewer	I-Application
or	O
similar	O
type	O
lacking	O
full	O
save	O
functionality	O
.	O
</s>
<s>
The	O
use	O
of	O
helper	B-Protocol
applications	I-Protocol
was	O
more	O
common	O
in	O
the	O
early	O
days	O
of	O
the	O
World	O
Wide	O
Web	O
,	O
when	O
HTML	O
and	O
file	O
formats	O
were	O
still	O
becoming	O
standardized	O
and	O
computers	O
were	O
less	O
powerful	O
.	O
</s>
<s>
Users	O
of	O
a	O
slower	O
computer	O
could	O
configure	O
their	O
browser	B-Application
to	O
hand	O
off	O
all	O
images	O
using	O
a	O
helper	B-Protocol
application	I-Protocol
,	O
which	O
would	O
cause	O
the	O
browser	B-Application
to	O
display	O
a	O
standard	O
icon	O
as	O
a	O
placeholder	O
.	O
</s>
<s>
In	O
addition	O
,	O
it	O
was	O
considered	O
important	O
for	O
early	O
browsers	B-Application
to	O
be	O
able	O
to	O
keep	O
an	O
image	O
illustrating	O
a	O
figure	O
or	O
graph	O
on	O
screen	O
while	O
scrolling	O
through	O
a	O
long	O
scientific	O
paper	O
and	O
having	O
the	O
image	O
displayed	O
in	O
an	O
external	O
window	O
while	O
the	O
browser	B-Application
window	O
was	O
scrolled	O
allowed	O
that	O
.	O
</s>
