<s>
Qpopper	B-Protocol
was	O
one	O
of	O
the	O
oldest	O
and	O
most	O
popular	O
server	O
implementations	O
of	O
POP3	B-Protocol
.	O
</s>
<s>
As	O
a	O
free	O
and	O
open-source	O
server	O
distributed	O
under	O
BSD	B-Operating_System
style	I-Operating_System
license	O
,	O
it	O
was	O
a	O
common	O
choice	O
for	O
Internet	O
Service	O
Providers	O
,	O
schools	O
,	O
corporations	O
,	O
and	O
other	O
organizations	O
.	O
</s>
<s>
Qpopper	B-Protocol
is	O
no	O
longer	O
maintained	O
.	O
</s>
<s>
Qpopper	B-Protocol
was	O
distributed	O
by	O
Qualcomm	O
as	O
source	O
code	O
;	O
other	O
parties	O
offer	O
pre-compiled	O
or	O
pre-configured	O
versions	O
for	O
various	O
platforms	O
.	O
</s>
<s>
Qpopper	B-Protocol
ran	O
on	O
a	O
wide	O
variety	O
of	O
platforms	O
,	O
including	O
virtually	O
all	O
Unix	O
and	O
Linux	O
distribution	O
,	O
Mac	O
OS	O
X	O
,	O
and	O
even	O
Windows	O
under	O
cygwin	B-Language
.	O
</s>
<s>
Qpopper	B-Protocol
was	O
generally	O
recognized	O
as	O
fast	O
,	O
stable	O
,	O
and	O
secure	O
.	O
</s>
<s>
Because	O
mbox	O
is	O
a	O
linear	O
format	O
in	O
which	O
messages	O
are	O
stored	O
sequentially	O
,	O
Qpopper	B-Protocol
supports	O
a	O
number	O
of	O
optimizations	O
to	O
improve	O
speed	O
and	O
scalability	O
,	O
including	O
a	O
cache	O
file	O
to	O
maintain	O
mailbox	O
state	O
between	O
sessions	O
,	O
and	O
several	O
optional	O
I/O	O
techniques	O
.	O
</s>
<s>
Qpopper	B-Protocol
started	O
out	O
as	O
"	O
popper	O
"	O
around	O
1989	O
at	O
the	O
University	O
of	O
California	O
,	O
Berkeley	O
.	O
</s>
<s>
Qualcomm	O
took	O
it	O
over	O
about	O
1993	O
,	O
and	O
renamed	O
it	O
"	O
Qpopper	B-Protocol
"	O
.	O
</s>
<s>
Qualcomm	O
's	O
original	O
goal	O
was	O
to	O
promote	O
the	O
availability	O
of	O
correct	O
and	O
modern	O
servers	O
for	O
the	O
Eudora	B-Operating_System
mail	B-Protocol
client	I-Protocol
to	O
use	O
,	O
and	O
also	O
to	O
provide	O
a	O
platform	O
for	O
newer	O
extensions	O
.	O
</s>
