<s>
The	O
Z	B-Application
shell	I-Application
(	O
Zsh	B-Application
)	O
is	O
a	O
Unix	B-Application
shell	I-Application
that	O
can	O
be	O
used	O
as	O
an	O
interactive	B-General_Concept
login	O
shell	B-Operating_System
and	O
as	O
a	O
command	O
interpreter	O
for	O
shell	B-Language
scripting	I-Language
.	O
</s>
<s>
Zsh	B-Application
is	O
an	O
extended	O
Bourne	B-Device
shell	I-Device
with	O
many	O
improvements	O
,	O
including	O
some	O
features	O
of	O
Bash	B-Operating_System
,	O
ksh	B-Language
,	O
and	O
tcsh	B-Language
.	O
</s>
<s>
Zsh	B-Application
was	O
created	O
by	O
Paul	O
Falstad	O
in	O
1990	O
while	O
he	O
was	O
a	O
student	O
at	O
Princeton	O
University	O
.	O
</s>
<s>
It	O
combines	O
features	O
from	O
both	O
ksh	B-Language
and	O
tcsh	B-Language
,	O
offering	O
functionality	O
such	O
as	O
programmable	O
command-line	O
completion	O
,	O
extended	O
file	B-Language
globbing	I-Language
,	O
improved	O
variable/array	O
handling	O
,	O
and	O
themeable	O
prompts	O
.	O
</s>
<s>
Zsh	B-Application
is	O
available	O
for	O
Microsoft	B-Application
Windows	I-Application
as	O
part	O
of	O
the	O
UnxUtils	B-Application
collection	O
and	O
has	O
been	O
adopted	O
as	O
the	O
default	O
shell	B-Operating_System
for	O
macOS	B-Device
Catalina	I-Device
and	O
Kali	O
Linux	O
.	O
</s>
<s>
The	O
"	O
Oh	O
My	O
Zsh	B-Application
"	O
user	O
community	O
website	O
provides	O
a	O
platform	O
for	O
third-party	O
plug-ins	O
and	O
themes	O
,	O
featuring	O
a	O
large	O
and	O
active	O
contributor	O
base	O
.	O
</s>
<s>
Paul	O
Falstad	O
wrote	O
the	O
first	O
version	O
of	O
Zsh	B-Application
in	O
1990	O
while	O
a	O
student	O
at	O
Princeton	O
University	O
.	O
</s>
<s>
The	O
name	O
zsh	B-Application
derives	O
from	O
the	O
name	O
of	O
Yale	O
professor	O
Zhong	O
Shao	O
(	O
then	O
a	O
teaching	O
assistant	O
at	O
Princeton	O
University	O
)	O
–	O
Paul	O
Falstad	O
regarded	O
Shao	O
's	O
login-id	O
,	O
"	O
zsh	B-Application
"	O
,	O
as	O
a	O
good	O
name	O
for	O
a	O
shell	B-Operating_System
.	O
</s>
<s>
Zsh	B-Application
was	O
at	O
first	O
intended	O
to	O
be	O
a	O
subset	O
of	O
csh	B-Operating_System
for	O
the	O
Amiga	B-Device
,	O
but	O
expanded	O
far	O
beyond	O
that	O
.	O
</s>
<s>
By	O
the	O
time	O
of	O
the	O
release	O
of	O
version	O
1.0	O
in	O
1990	O
the	O
aim	O
was	O
to	O
be	O
a	O
cross	O
between	O
ksh	B-Language
and	O
tcsh	B-Language
–	O
a	O
powerful	O
"	O
command	O
and	O
programming	O
language	O
"	O
that	O
is	O
well-designed	O
and	O
logical	O
(	O
like	O
ksh	B-Language
)	O
,	O
but	O
also	O
built	O
for	O
humans	O
(	O
like	O
tcsh	B-Language
)	O
,	O
with	O
all	O
the	O
neat	O
features	O
like	O
spell	B-Application
checking	I-Application
,	O
login/logout	O
watching	O
and	O
termcap	O
support	O
that	O
were	O
"	O
probably	O
too	O
weird	O
to	O
make	O
it	O
into	O
an	O
AT&T	O
product	O
"	O
.	O
</s>
<s>
Zsh	B-Application
is	O
available	O
as	O
a	O
separate	O
package	O
for	O
Microsoft	B-Application
Windows	I-Application
as	O
part	O
of	O
the	O
UnxUtils	B-Application
collection	O
of	O
native	B-Language
Win32	B-Library
ports	O
of	O
common	O
GNU	B-Operating_System
Unix-like	O
utilities	O
.	O
</s>
<s>
In	O
2019	O
,	O
macOS	B-Device
Catalina	I-Device
adopted	O
Zsh	B-Application
as	O
the	O
default	O
login	O
shell	B-Operating_System
,	O
replacing	O
the	O
GPLv2	O
licensed	O
version	O
of	O
Bash	B-Operating_System
,	O
and	O
when	O
Bash	B-Operating_System
is	O
run	O
interactively	B-General_Concept
on	O
Catalina	O
,	O
a	O
warning	O
is	O
shown	O
by	O
default	O
.	O
</s>
<s>
In	O
2020	O
,	O
Kali	O
Linux	O
adopted	O
Zsh	B-Application
as	O
the	O
default	O
shell	B-Operating_System
since	O
its	O
2020.4	O
release	O
.	O
</s>
<s>
Loadable	O
modules	O
,	O
providing	O
among	O
other	O
things	O
:	O
full	O
TCP	B-Protocol
and	O
Unix	B-Protocol
domain	I-Protocol
socket	I-Protocol
controls	O
,	O
an	O
FTP	B-Protocol
client	O
,	O
and	O
extended	O
math	O
functions	O
.	O
</s>
<s>
A	O
user	O
community	O
website	O
known	O
as	O
"	O
Oh	O
My	O
Zsh	B-Application
"	O
collects	O
third-party	O
plug-ins	O
and	O
themes	O
for	O
the	O
Z	B-Application
shell	I-Application
.	O
</s>
<s>
As	O
of	O
2021	O
,	O
their	O
GitHub	B-Application
repository	O
has	O
over	O
1900	O
contributors	O
,	O
over	O
300	O
plug-ins	O
,	O
and	O
over	O
140	O
themes	O
.	O
</s>
