<s>
Compact	B-Operating_System
Pro	I-Operating_System
is	O
a	O
software	O
data	B-General_Concept
compression	I-General_Concept
utility	O
for	O
archiving	O
and	O
compressing	O
files	O
on	O
the	O
Apple	B-Device
Macintosh	I-Device
platform	O
.	O
</s>
<s>
It	O
was	O
a	O
major	O
competitor	O
to	O
StuffIt	B-Application
in	O
the	O
early	O
1990s	O
,	O
producing	O
smaller	O
archives	O
in	O
less	O
time	O
,	O
able	O
to	O
create	O
self-extracting	B-General_Concept
archives	I-General_Concept
without	O
the	O
use	O
of	O
an	O
external	O
program	O
,	O
as	O
well	O
as	O
being	O
distributed	O
via	O
shareware	B-License
which	O
greatly	O
helped	O
its	O
popularity	O
.	O
</s>
<s>
When	O
it	O
was	O
introduced	O
in	O
the	O
early	O
1990s	O
,	O
Compact	B-Operating_System
Pro	I-Operating_System
(	O
originally	O
known	O
as	O
"	O
Compactor	O
"	O
)	O
competed	O
against	O
StuffIt	B-Application
,	O
which	O
had	O
been	O
suffering	O
from	O
neglect	O
after	O
its	O
original	O
developer	O
moved	O
on	O
to	O
other	O
projects	O
.	O
</s>
<s>
Compact	B-Operating_System
Pro	I-Operating_System
sported	O
a	O
clean	O
interface	O
and	O
a	O
variety	O
of	O
new	O
features	O
which	O
quickly	O
made	O
it	O
a	O
favorite	O
among	O
the	O
digerati	O
.	O
</s>
<s>
It	O
quickly	O
drove	O
StuffIt	B-Application
from	O
the	O
leadership	O
position	O
and	O
became	O
very	O
popular	O
on	O
BBS	B-Application
systems	O
.	O
</s>
<s>
StuffIt	B-Application
3.0	O
fought	O
back	O
with	O
an	O
even	O
more	O
powerful	O
compression	B-General_Concept
algorithm	I-General_Concept
,	O
a	O
shareware	B-License
version	O
called	O
StuffIt	B-Application
Lite	O
with	O
most	O
of	O
the	O
same	O
features	O
,	O
and	O
the	O
freeware	B-License
StuffIt	B-Operating_System
Expander	I-Operating_System
which	O
could	O
decompress	O
StuffIt	B-Application
archives	O
and	O
Compact	B-Operating_System
Pro	I-Operating_System
archives	O
.	O
</s>
<s>
Compact	B-Operating_System
Pro	I-Operating_System
never	O
really	O
regained	O
its	O
momentum	O
after	O
the	O
release	O
of	O
StuffIt	B-Operating_System
Expander	I-Operating_System
.	O
</s>
<s>
Compact	B-Operating_System
Pro	I-Operating_System
also	O
served	O
as	O
the	O
inspiration	O
for	O
ZipIt	B-Application
,	O
a	O
PKZip-compatible	O
archiver	O
that	O
was	O
expressly	O
designed	O
to	O
look	O
and	O
work	O
like	O
Compact	B-Operating_System
Pro	I-Operating_System
.	O
</s>
<s>
Like	O
most	O
archiver	O
systems	O
,	O
Compact	B-Operating_System
Pro	I-Operating_System
's	O
primary	O
purpose	O
was	O
to	O
package	O
up	O
and	O
compress	O
files	O
for	O
transmission	O
,	O
then	O
extract	O
them	O
again	O
on	O
the	O
other	O
side	O
of	O
the	O
link	O
.	O
</s>
<s>
Unlike	O
most	O
systems	O
,	O
Compact	B-Operating_System
Pro	I-Operating_System
used	O
a	O
non-modal	O
Mac-like	O
UI	O
that	O
was	O
widely	O
lauded	O
in	O
the	O
press	O
.	O
</s>
<s>
Some	O
of	O
the	O
more	O
notable	O
features	O
included	O
the	O
ability	O
to	O
extract	O
everything	O
from	O
an	O
archive	O
by	O
double-clicking	O
on	O
it	O
in	O
the	O
Finder	B-Application
with	O
the	O
key	O
held	O
down	O
,	O
and	O
automatically	O
recognizing	O
and	O
converting	O
BinHex	O
formatted	O
files	O
back	O
into	O
native	O
format	O
without	O
a	O
separate	O
step	O
.	O
</s>
<s>
Compact	B-Operating_System
Pro	I-Operating_System
also	O
featured	O
an	O
easy-to-use	O
system	O
for	O
splitting	O
files	O
into	O
parts	O
to	O
fit	O
on	O
floppy	B-Device
disks	I-Device
,	O
a	O
feature	O
that	O
most	O
archivers	O
implemented	O
in	O
an	O
external	O
program	O
,	O
if	O
at	O
all	O
.	O
</s>
<s>
An	O
odd	O
,	O
but	O
oft-used	O
,	O
feature	O
was	O
the	O
ability	O
to	O
include	O
images	O
and	O
notes	O
that	O
would	O
display	O
when	O
the	O
archive	O
was	O
opened	O
,	O
using	O
the	O
same	O
basic	O
mechanism	O
as	O
TeachText	B-Operating_System
.	O
</s>
<s>
Compact	B-Operating_System
Pro	I-Operating_System
also	O
included	O
the	O
ability	O
to	O
produce	O
self-extracting	B-General_Concept
archives	I-General_Concept
.	O
</s>
<s>
Although	O
this	O
was	O
becoming	O
common	O
in	O
archivers	O
at	O
the	O
time	O
,	O
its	O
particular	O
implementation	O
was	O
notable	O
because	O
the	O
extractor	O
"	O
stub	O
"	O
code	O
was	O
quite	O
small	O
at	O
about	O
13kB	O
(	O
compared	O
to	O
StuffIt	B-Application
at	O
38kB	O
)	O
.	O
</s>
<s>
In	O
an	O
era	O
of	O
14400bit/s	O
modems	B-Application
,	O
this	O
was	O
a	O
worthwhile	O
savings	O
.	O
</s>
<s>
Compact	B-Operating_System
Pro	I-Operating_System
's	O
stub	O
could	O
also	O
expand	O
files	O
that	O
had	O
been	O
split	O
into	O
parts	O
,	O
a	O
rare	O
feature	O
at	O
the	O
time	O
.	O
</s>
<s>
At	O
the	O
time	O
of	O
its	O
introduction	O
,	O
Compact	B-Operating_System
Pro	I-Operating_System
offered	O
,	O
by	O
far	O
,	O
the	O
fastest	O
and	O
best	O
compression	O
on	O
the	O
Mac	B-Device
.	O
</s>
<s>
In	O
use	O
,	O
"	O
Compactor	O
files	O
were	O
never	O
more	O
than	O
1%	O
larger	O
than	O
StuffIt	B-Application
Deluxe	O
's	O
"	O
Better	O
"	O
/	O
"	O
Best	O
Guess	O
"	O
modes	O
,	O
but	O
anywhere	O
from	O
25%	O
to	O
400%	O
faster.	O
"	O
</s>
<s>
Ironically	O
,	O
Compact	B-Operating_System
Pro	I-Operating_System
was	O
even	O
faster	O
than	O
StuffIt	B-Application
at	O
extracting	O
StuffIt	B-Application
files	O
,	O
often	O
at	O
least	O
double	O
the	O
performance	O
.	O
</s>
<s>
Testing	O
in	O
the	O
late	O
1990s	O
show	O
it	O
remaining	O
significantly	O
faster	O
and	O
smaller	O
than	O
versions	O
of	O
StuffIt	B-Application
from	O
years	O
later	O
.	O
</s>
<s>
Normal	O
archives	O
created	O
with	O
Compact	B-Operating_System
Pro	I-Operating_System
use	O
the	O
file	B-Operating_System
extension	O
,	O
while	O
self-extracting	O
versions	O
used	O
.	O
</s>
<s>
File	B-Operating_System
extensions	O
are	O
not	O
normally	O
needed	O
on	O
the	O
Mac	B-Device
,	O
but	O
were	O
commonly	O
used	O
on	O
archives	O
because	O
they	O
would	O
typically	O
be	O
stored	O
on	O
some	O
other	O
system	O
that	O
would	O
normally	O
require	O
them	O
(	O
PCs	O
for	O
instance	O
)	O
.	O
</s>
