<s>
Dunnet	B-Operating_System
is	O
a	O
surreal	O
,	O
cyberpunk	O
text	O
adventure	O
written	O
by	O
Ron	O
Schnell	O
,	O
based	O
on	O
a	O
game	O
he	O
wrote	O
in	O
1982	O
.	O
</s>
<s>
It	O
was	O
first	O
written	O
in	O
Maclisp	B-Language
for	O
the	O
DECSYSTEM-20	B-Device
,	O
then	O
ported	O
to	O
Emacs	B-Operating_System
Lisp	I-Operating_System
in	O
1992	O
.	O
</s>
<s>
Since	O
1994	O
the	O
game	O
has	O
shipped	O
with	O
GNU	B-Application
Emacs	I-Application
;	O
it	O
also	O
has	O
been	O
included	O
with	O
XEmacs	B-Language
.	O
</s>
<s>
The	O
game	O
starts	O
out	O
with	O
the	O
player	O
standing	O
at	O
the	O
end	O
of	O
a	O
dirt	O
road	O
,	O
but	O
it	O
turns	O
to	O
the	O
surreal	O
when	O
players	O
realize	O
that	O
they	O
are	O
actually	O
walking	O
around	O
inside	O
a	O
Unix	B-Application
system	I-Application
,	O
and	O
teleporting	B-Protocol
themselves	O
around	O
the	O
Arpanet	O
.	O
</s>
<s>
Dunnet	B-Operating_System
is	O
playable	O
on	O
any	O
operating	O
system	O
with	O
the	O
Emacs	O
editor	O
.	O
</s>
<s>
Emacs	O
comes	O
with	O
most	O
Unices	B-Operating_System
,	O
including	O
macOS	B-Application
(	O
prior	O
to	O
version	O
10.15	O
Catalina	B-Device
)	O
and	O
distributions	O
of	O
Linux	B-Application
.	O
</s>
<s>
Several	O
articles	O
targeted	O
to	O
Mac	B-Application
OS	I-Application
X	O
owners	O
have	O
recommended	O
it	O
as	O
an	O
easter	O
egg	O
as	O
a	O
game	O
that	O
can	O
be	O
run	O
in	O
Terminal.app	O
.	O
</s>
<s>
It	O
can	O
be	O
run	O
by	O
running	O
emacs	O
-batch	O
-l	O
dunnet	B-Operating_System
in	O
a	O
shell	B-Operating_System
or	O
the	O
key	O
sequence	O
M-x	O
dunnet	B-Operating_System
within	O
Emacs	O
,	O
the	O
former	O
being	O
the	O
preferred	O
and	O
official	O
way	O
to	O
run	O
it	O
.	O
</s>
<s>
Dunnet	B-Operating_System
was	O
used	O
as	O
a	O
benchmark	O
in	O
the	O
effort	O
to	O
port	O
Emacs	B-Operating_System
Lisp	I-Operating_System
to	O
Guile	B-Application
,	O
progressing	O
from	O
running	O
standalone	O
games	O
to	O
running	O
the	O
entire	O
Emacs	O
system	O
in	O
less	O
than	O
a	O
person-year	O
of	O
work	O
.	O
</s>
