<s>
zoo	B-Application
is	O
a	O
data	B-General_Concept
compression	I-General_Concept
program	O
and	O
format	O
developed	O
by	O
Rahul	O
Dhesi	O
in	O
the	O
mid-1980s	O
.	O
</s>
<s>
The	O
format	O
is	O
based	O
on	O
the	O
LZW	B-Algorithm
compression	I-Algorithm
algorithm	I-Algorithm
and	O
compressed	O
files	O
are	O
identified	O
by	O
the	O
.zoo	B-Application
file	O
extension	O
.	O
</s>
<s>
Program	O
source	O
code	O
was	O
originally	O
published	O
on	O
the	O
comp.sources.misc	O
Usenet	B-Application
newsgroup	O
,	O
and	O
was	O
compatible	O
with	O
a	O
variety	O
of	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
Binaries	O
were	O
also	O
published	O
for	O
the	O
MS-DOS	B-Application
and	O
AmigaOS	B-Application
user	O
communities	O
.	O
</s>
<s>
Zoo	B-Application
archives	O
can	O
store	O
multiple	O
"	O
generations	O
"	O
of	O
a	O
file	O
;	O
if	O
files	O
are	O
added	O
to	O
an	O
archive	O
with	O
the	O
same	O
pathname	O
yet	O
more	O
recent	O
date	O
,	O
if	O
generations	O
are	O
enabled	O
for	O
the	O
archive	O
the	O
older	O
version(s )	O
will	O
be	O
retained	O
(	O
with	O
a	O
semicolon	O
and	O
version	O
number	O
,	O
similar	O
to	O
version	O
numbers	O
in	O
the	O
VMS	O
and	O
RT-11	O
operating	O
systems	O
)	O
as	O
the	O
new	O
file	O
is	O
added	O
.	O
</s>
