<s>
A	O
MOO	B-Application
(	O
"	O
MUD	B-Application
,	O
object-oriented	B-Language
"	O
)	O
is	O
a	O
text-based	O
online	O
virtual	B-Application
reality	I-Application
system	O
to	O
which	O
multiple	O
users	O
(	O
players	O
)	O
are	O
connected	O
at	O
the	O
same	O
time	O
.	O
</s>
<s>
The	O
term	O
MOO	B-Application
is	O
used	O
in	O
two	O
distinct	O
,	O
but	O
related	O
,	O
senses	O
.	O
</s>
<s>
One	O
is	O
to	O
refer	O
to	O
those	O
programs	O
descended	O
from	O
the	O
original	O
MOO	B-Application
server	O
,	O
and	O
the	O
other	O
is	O
to	O
refer	O
to	O
any	O
MUD	B-Application
that	O
uses	O
object-oriented	B-Language
techniques	O
to	O
organize	O
its	O
database	O
of	O
objects	O
,	O
particularly	O
if	O
it	O
does	O
so	O
in	O
a	O
similar	O
fashion	O
to	O
the	O
original	O
MOO	B-Application
or	O
its	O
derivatives	O
.	O
</s>
<s>
Most	O
of	O
this	O
article	O
refers	O
to	O
the	O
original	O
MOO	B-Application
and	O
its	O
direct	O
descendants	O
,	O
but	O
see	O
non-descendant	O
MOOs	B-Application
for	O
a	O
list	O
of	O
MOO-like	O
systems	O
.	O
</s>
<s>
The	O
original	O
MOO	B-Application
server	O
was	O
authored	O
by	O
Stephen	O
White	O
,	O
based	O
on	O
his	O
experience	O
from	O
creating	O
the	O
programmable	O
TinyMUCK	B-Application
system	O
.	O
</s>
<s>
One	O
of	O
the	O
most	O
distinguishing	O
features	O
of	O
a	O
MOO	B-Application
is	O
that	O
its	O
users	O
can	O
perform	O
object-oriented	B-Language
programming	I-Language
within	O
the	O
server	O
,	O
ultimately	O
expanding	O
and	O
changing	O
how	O
it	O
behaves	O
to	O
everyone	O
.	O
</s>
<s>
Examples	O
of	O
such	O
changes	O
include	O
authoring	O
new	O
rooms	O
and	O
objects	O
,	O
creating	O
new	O
generic	O
objects	O
for	O
others	O
to	O
use	O
,	O
and	O
changing	O
the	O
way	O
the	O
MOO	B-Application
interface	O
operates	O
.	O
</s>
<s>
The	O
programming	O
language	O
used	O
for	O
extension	O
is	O
the	O
MOO	B-Application
programming	I-Application
language	I-Application
,	O
and	O
many	O
MOOs	B-Application
feature	O
convenient	O
libraries	O
of	O
verbs	O
that	O
can	O
be	O
used	O
by	O
programmers	O
in	O
their	O
coding	O
known	O
as	O
Utilities	O
.	O
</s>
<s>
The	O
MOO	B-Application
programming	I-Application
language	I-Application
is	O
a	O
domain-specific	B-Language
language	I-Language
.	O
</s>
<s>
MOOs	B-Application
are	O
network	O
accessible	O
,	O
multi-user	O
,	O
programmable	O
,	O
interactive	O
systems	O
well-suited	O
to	O
the	O
construction	O
of	O
text-based	O
adventure	O
games	O
,	O
conferencing	O
systems	O
,	O
and	O
other	O
collaborative	O
software	O
.	O
</s>
<s>
Their	O
most	O
common	O
use	O
,	O
however	O
,	O
is	O
as	O
multi-participant	O
,	O
low-bandwidth	O
virtual	B-Application
realities	I-Application
.	O
</s>
<s>
They	O
have	O
been	O
used	O
in	O
academic	O
environments	O
for	O
distance	O
education	O
,	O
collaboration	O
(	O
such	O
as	O
Diversity	B-Application
University	I-Application
)	O
,	O
group	O
decision	O
systems	O
,	O
and	O
teaching	O
object-oriented	B-Language
concepts	O
;	O
but	O
others	O
are	O
primarily	O
social	O
in	O
nature	O
,	O
or	O
used	O
for	O
role-playing	O
video	O
games	O
,	O
or	O
simply	O
to	O
take	O
advantage	O
of	O
the	O
programming	O
possibilities	O
.	O
</s>
<s>
Most	O
commonly	O
,	O
MOOs	B-Application
are	O
connected	O
to	O
by	O
users	O
using	O
a	O
client	B-Protocol
which	O
speaks	O
the	O
telnet	B-Protocol
protocol	O
,	O
which	O
provides	O
a	O
stay-alive	O
connection	O
with	O
the	O
host	O
,	O
to	O
relay	O
output	O
and	O
send	O
commands	O
.	O
</s>
<s>
Developments	O
in	O
cross-MOO	O
networking	B-Architecture
have	O
also	O
led	O
to	O
the	O
creation	O
of	O
SunNET	O
,	O
a	O
hubless	O
network	O
allowing	O
cross-MOO	O
communication	O
and	O
add	O
extra	O
possibilities	O
to	O
cross-MOO	O
development	O
,	O
including	O
networked	O
channels	O
.	O
</s>
<s>
Most	O
of	O
these	O
MOOs	B-Application
hosted	O
online	O
classes	O
or	O
other	O
early	O
versions	O
of	O
distance	O
education	O
.	O
</s>
<s>
Every	O
MOO	B-Application
stores	O
the	O
content	O
and	O
state	O
of	O
all	O
its	O
objects	O
within	O
a	O
persistent	B-Application
object	B-Application
database	I-Application
,	O
which	O
keeps	O
objects	O
from	O
being	O
lost	O
by	O
a	O
reset	O
of	O
the	O
MOO	B-Application
server	O
software	O
or	O
the	O
computer	O
hosting	O
it	O
.	O
</s>
<s>
New	O
MOOs	B-Application
have	O
to	O
choose	O
a	O
starting	O
database	O
from	O
which	O
to	O
set	O
their	O
MOO	B-Application
up	O
,	O
or	O
they	O
can	O
use	O
a	O
minimal	O
one	O
which	O
contains	O
only	O
the	O
necessary	O
objects	O
to	O
start	O
a	O
MOO	B-Application
.	O
</s>
<s>
Every	O
object	O
in	O
the	O
MOO	B-Application
is	O
assigned	O
a	O
number	O
,	O
and	O
may	O
be	O
referred	O
to	O
by	O
this	O
number	O
,	O
prefixed	O
with	O
a	O
#	O
,	O
as	O
well	O
as	O
its	O
name	O
when	O
the	O
user	O
is	O
in	O
the	O
object	O
's	O
presence	O
.	O
</s>
<s>
Administrators	O
,	O
also	O
known	O
as	O
wizards	B-Application
,	O
who	O
can	O
manage	O
the	O
MOO	B-Application
,	O
and	O
assign	O
certain	O
global	O
names	O
to	O
these	O
objects	O
,	O
which	O
are	O
prefixed	O
with	O
$	O
,	O
a	O
process	O
known	O
as	O
corifying	O
.	O
</s>
<s>
MOO	B-Application
,	O
along	O
with	O
all	O
of	O
its	O
nephews	O
,	O
started	O
out	O
with	O
text	O
based	O
adventure	O
games	O
.	O
</s>
<s>
With	O
the	O
advent	O
of	O
the	O
internet	O
,	O
MUD	B-Application
was	O
formed	O
as	O
a	O
networked	O
version	O
of	O
one	O
of	O
those	O
games	O
.	O
</s>
<s>
Eventually	O
it	O
developed	O
into	O
a	O
tree	O
of	O
different	O
types	O
of	O
MUD	B-Application
,	O
with	O
MOO	B-Application
becoming	O
one	O
of	O
them	O
.	O
</s>
<s>
Stephen	O
White	O
(	O
also	O
known	O
by	O
the	O
handles	O
"	O
Ghondahrl	O
"	O
and	O
"	O
ghond	O
"	O
)	O
wrote	O
the	O
first	O
version	O
of	O
the	O
MOO	B-Application
server	O
,	O
which	O
was	O
released	O
on	O
May	O
2	O
,	O
1990	O
,	O
and	O
used	O
for	O
the	O
operation	O
of	O
a	O
server	O
called	O
"	O
AlphaMOO	O
"	O
.	O
</s>
<s>
He	O
dubbed	O
this	O
new	O
system	O
LambdaMOO	O
,	O
after	O
one	O
of	O
his	O
names	O
on	O
the	O
system	O
and	O
,	O
according	O
to	O
Curtis	O
,	O
"	O
because	O
it	O
's	O
a	O
key	O
word	O
in	O
some	O
of	O
the	O
other	O
non-mud	O
research	O
that	O
I	O
do.	O
"	O
</s>
<s>
The	O
new	O
system	O
was	O
announced	O
as	O
open	O
for	O
public	O
access	O
on	O
UseNet	B-Application
(	O
a	O
world-wide	O
bulletin	O
board	O
system	O
)	O
in	O
February	O
1991	O
(	O
Curtis	O
,	O
personal	O
communication	O
)	O
.	O
</s>
<s>
MOO	B-Application
was	O
originally	O
developed	O
as	O
a	O
MUD	B-Application
server	O
in	O
the	O
same	O
general	O
style	O
(	O
sharing	O
much	O
of	O
the	O
command	O
syntax	O
and	O
community	O
conventions	O
)	O
as	O
TinyMUD	O
.	O
</s>
<s>
There	O
are	O
currently	O
two	O
distributions	O
of	O
the	O
MOO	B-Application
server	O
code	O
.	O
</s>
<s>
The	O
more	O
popular	O
of	O
the	O
two	O
,	O
the	O
LambdaMOO	O
server	O
,	O
is	O
named	O
such	O
as	O
indication	O
of	O
the	O
close	O
historical	O
and	O
continuing	O
association	O
of	O
the	O
MOO	B-Application
server	O
code	O
with	O
the	O
first	O
public	O
MOO	B-Application
,	O
LambdaMOO	O
.	O
</s>
<s>
The	O
LambdaMOO	O
version	O
of	O
MOO	B-Application
that	O
gained	O
popularity	O
in	O
the	O
early	O
1990s	O
,	O
and	O
it	O
remains	O
the	O
most	O
widely	O
used	O
MOO	B-Application
distribution	O
.	O
</s>
<s>
Later	O
,	O
Erik	O
Ostrom	O
maintained	O
the	O
server	O
,	O
and	O
the	O
server	O
is	O
now	O
maintained	O
by	O
Ben	O
Jackson	O
and	O
Jay	O
Carlson	O
and	O
has	O
a	O
LambdaMOO	O
SourceForge.net	B-Application
project	O
.	O
</s>
<s>
Behavior	O
on	O
social	O
MOOs	B-Application
and	O
role-playing	O
MOOs	B-Application
has	O
been	O
shown	O
to	O
differ	O
.	O
</s>
<s>
The	O
majority	O
of	O
participants	O
(	O
60	O
percent	O
)	O
in	O
social	O
MOOs	B-Application
had	O
never	O
engaged	O
in	O
gender-switching	O
,	O
while	O
the	O
majority	O
(	O
56.7	O
percent	O
)	O
in	O
role-playing	O
MOOs	B-Application
had	O
done	O
so	O
.	O
</s>
<s>
Stunt	O
is	O
a	O
backward	O
compatible	O
fork	O
of	O
the	O
latest	O
MOO	B-Application
server	O
code	O
.	O
</s>
<s>
These	O
include	O
64-bit	O
integers	O
,	O
SQLite	O
support	O
,	O
Perl-compatible	O
regular	O
expressions	O
,	O
background	O
threaded	O
functions	O
,	O
Argon2id	O
hashing	O
,	O
telnet	B-Protocol
IAC	O
capturing	O
,	O
profiling	O
support	O
,	O
performance	O
improvements	O
,	O
and	O
dozens	O
of	O
additional	O
built-in	O
functions	O
and	O
improvements	O
.	O
</s>
<s>
Some	O
servers	O
use	O
"	O
MOO	B-Application
"	O
style	O
object-oriented	B-Language
characteristics	O
without	O
being	O
descended	O
from	O
the	O
original	O
MOO	B-Application
server	O
,	O
in	O
the	O
sense	O
that	O
they	O
use	O
little	O
or	O
none	O
of	O
that	O
server	O
's	O
source	O
code	O
and	O
use	O
internal	O
languages	O
that	O
are	O
more	O
or	O
less	O
incompatible	O
with	O
the	O
MOO	B-Application
programming	I-Application
language	I-Application
.	O
</s>
<s>
Stephen	O
White	O
went	O
on	O
to	O
write	O
a	O
new	O
and	O
similar	O
system	O
called	O
CoolMUD	O
,	O
although	O
it	O
never	O
obtained	O
the	O
same	O
wide	O
userbase	O
as	O
MOO	B-Application
.	O
</s>
<s>
Another	O
,	O
later	O
,	O
attempt	O
at	O
a	O
programmable	O
object-oriented	B-Language
MUD	B-Application
server	O
was	O
ColdMUD	O
,	O
written	O
by	O
Greg	O
Hudson	O
and	O
later	O
maintained	O
by	O
Brandon	O
Gillespie	O
under	O
the	O
name	O
"	O
Genesis	O
"	O
.	O
</s>
<s>
One	O
unusual	O
MOO	B-Application
with	O
no	O
real	O
relationship	O
to	O
the	O
original	O
MOO	B-Application
is	O
called	O
mooix	O
.	O
</s>
<s>
mooix	O
is	O
unique	O
among	O
MUDs	B-Application
in	O
that	O
it	O
uses	O
the	O
underlying	O
UNIX	O
operating	O
system	O
to	O
handle	O
all	O
of	O
the	O
multitasking	B-Operating_System
and	O
networking	B-Architecture
issues	O
.	O
</s>
<s>
Several	O
unique	O
side	O
effects	O
result	O
from	O
this	O
,	O
one	O
of	O
which	O
is	O
that	O
the	O
MOO	B-Application
can	O
be	O
programmed	O
in	O
any	O
language	O
.	O
</s>
<s>
mooix	O
was	O
written	O
after	O
a	O
failed	O
attempt	O
by	O
Joey	O
Hess	O
to	O
write	O
a	O
MOO	B-Application
entirely	O
in	O
Perl	O
,	O
called	O
perlmoo	O
.	O
</s>
<s>
Participants	O
(	O
usually	O
referred	O
to	O
as	O
users	O
)	O
connect	O
to	O
a	O
MOO	B-Application
using	O
telnet	B-Protocol
or	O
some	O
other	O
,	O
more	O
specialized	O
,	O
client	B-Protocol
program	I-Protocol
.	O
</s>
<s>
Almost	O
every	O
command	O
is	O
parsed	O
by	O
the	O
server	O
into	O
a	O
call	O
on	O
a	O
MOO	B-Application
procedure	O
,	O
or	O
verb	O
,	O
which	O
actually	O
does	O
the	O
work	O
.	O
</s>
<s>
Thus	O
,	O
programming	O
in	O
the	O
MOO	B-Application
programming	I-Application
language	I-Application
is	O
a	O
central	O
part	O
of	O
making	O
non-trivial	O
extensions	O
to	O
the	O
database	O
and	O
hence	O
the	O
virtual	B-Application
reality	I-Application
.	O
</s>
<s>
All	O
MOOs	B-Application
provide	O
a	O
flag	O
called	O
Wizard	B-Application
;	O
when	O
set	O
on	O
a	O
player	O
,	O
the	O
player	O
gains	O
the	O
ability	O
to	O
view	O
and	O
modify	O
nearly	O
everything	O
in	O
the	O
MOOs	B-Application
database	O
.	O
</s>
<s>
Such	O
players	O
are	O
called	O
Wizards	B-Application
,	O
and	O
usually	O
form	O
the	O
basis	O
for	O
MOO	B-Application
administration	O
.	O
</s>
<s>
Designated	O
owners	O
of	O
a	O
MOO	B-Application
are	O
sometimes	O
referred	O
to	O
as	O
Archwizards	O
.	O
</s>
<s>
These	O
wizards	B-Application
can	O
restrict	O
access	O
to	O
the	O
MOO	B-Application
,	O
as	O
well	O
as	O
make	O
news	O
postings	O
and	O
monitor	O
logs	O
.	O
</s>
<s>
Wizard	B-Application
permissions	O
are	O
needed	O
for	O
modification	O
and	O
even	O
execution	O
of	O
verbs	O
and	O
properties	O
for	O
which	O
the	O
user	O
does	O
not	O
own	O
,	O
or	O
is	O
not	O
publicly	O
readable/writable	O
.	O
</s>
<s>
Builders	O
are	O
players	O
who	O
are	O
given	O
the	O
limited	O
ability	O
to	O
create	O
objects	O
and	O
areas	O
in	O
a	O
MOO	B-Application
,	O
whereas	O
programmers	O
can	O
also	O
program	O
on	O
the	O
MOO	B-Application
.	O
</s>
<s>
It	O
was	O
the	O
first	O
public	O
MOO	B-Application
.	O
</s>
<s>
JaysHouseMOO	O
was	O
a	O
social	O
MOO	B-Application
started	O
by	O
Jay	O
Carlson	O
at	O
Minnesota	O
State	O
University	O
at	O
Mankato	O
in	O
1992	O
.	O
</s>
<s>
It	O
had	O
the	O
first	O
gopher	O
server	O
implemented	O
in	O
MOO	B-Application
language	I-Application
.	O
</s>
<s>
During	O
the	O
90	O
's	O
,	O
it	O
was	O
considered	O
the	O
hangout	O
of	O
the	O
MOO	B-Application
programmer	O
elite	O
.	O
</s>
<s>
(	O
The	O
Digital	O
Subway	O
)	O
founded	O
in	O
1994	O
as	O
part	O
of	O
De	O
Digitale	O
Stad	O
(	O
The	O
Digital	O
City	O
of	O
Amsterdam	O
)	O
and	O
one	O
of	O
the	O
first	O
Dutch	O
MOOs	B-Application
.	O
</s>
<s>
BayMOO	O
is	O
a	O
social	O
MOO	B-Application
founded	O
in	O
October	O
1993	O
.	O
</s>
<s>
BayMOO	O
also	O
hosted	O
FactoryNet	O
a	O
custom	O
MOO	B-Application
for	O
NIST	O
.	O
</s>
<s>
In	O
December	O
1994	O
it	O
was	O
one	O
of	O
the	O
MOOs	B-Application
chosen	O
to	O
host	O
Aerosmith	O
's	O
four-day	O
"	O
Cyberspace	O
Tour	O
"	O
which	O
was	O
co-sponsored	O
by	O
EFF	O
.	O
</s>
<s>
IDMOO	O
is	O
a	O
New	O
York-based	O
MOO	B-Application
that	O
was	O
started	O
by	O
some	O
programmers	O
from	O
LambdaMOO	O
and	O
PMCMOO	O
who	O
felt	O
that	O
MOO	B-Application
spaces	O
were	O
becoming	O
too	O
dominated	O
by	O
societal	O
conventions	O
developed	O
for	O
nonvirtual	O
spaces	O
.	O
</s>
<s>
SchoolNet	B-General_Concept
MOO	B-Application
started	O
in	O
the	O
mid	O
1990s	O
and	O
was	O
funded	O
by	O
SchoolNet	B-General_Concept
until	O
1998	O
,	O
when	O
it	O
was	O
renamed	O
to	O
MOO	B-Application
Canada	O
,	O
Eh	O
?	O
</s>
<s>
SchoolNet	B-General_Concept
MOO	B-Application
was	O
particularly	O
popular	O
in	O
the	O
Ottawa	O
,	O
Canada	O
region	O
due	O
to	O
its	O
use	O
by	O
Virtual	O
Ventures	O
at	O
Carleton	O
University	O
,	O
and	O
a	O
member	O
of	O
Actua	O
(	O
known	O
as	O
YES-VACC	O
at	O
these	O
times	O
)	O
as	O
a	O
computer	O
programming	O
educational	O
platform	O
for	O
youths	O
of	O
ages	O
8	O
–	O
18	O
.	O
</s>
<s>
Diversity	B-Application
University	I-Application
,	O
the	O
first	O
dedicated	O
educational	O
MOO	B-Application
,	O
created	O
by	O
Jeanne	O
McWhorter	O
in	O
1993	O
.	O
</s>
<s>
Postmodern	O
Culture	O
MOO	B-Application
(	O
PMC2	O
or	O
PMCMOO	O
)	O
was	O
a	O
MOO	B-Application
hosted	O
by	O
the	O
Institute	O
for	O
Advanced	O
Technologies	O
in	O
the	O
Humanities	O
(	O
IATH	O
)	O
at	O
University	O
of	O
Virginia	O
that	O
was	O
very	O
active	O
in	O
the	O
mid-1990s	O
.	O
</s>
<s>
,	O
a	O
constructionist	O
learning	O
educational	O
MOO	B-Application
designed	O
for	O
teaching	O
children	O
ages	O
9	O
to	O
13	O
.	O
</s>
<s>
It	O
was	O
developed	O
by	O
Amy	O
S	O
.	O
Bruckman	O
in	O
1996	O
as	O
her	O
doctoral	O
dissertation	O
work	O
,	O
and	O
cited	O
among	O
"	O
the	O
most	O
notable	O
MOO	B-Application
research	O
in	O
education	O
"	O
.	O
</s>
<s>
BioMOO	O
was	O
a	O
professional	O
MOO	B-Application
started	O
by	O
Gustavo	O
Glusman	O
and	O
Jaime	O
Prilusky	O
at	O
the	O
Weizmann	O
Institute	O
of	O
Science	O
in	O
1993	O
.	O
</s>
<s>
It	O
was	O
a	O
virtual	O
place	O
for	O
Biology	O
researchers	O
to	O
meet	O
to	O
brainstorm	O
,	O
hold	O
colloquia	O
and	O
conferences	O
,	O
and	O
explore	O
the	O
serious	O
side	O
of	O
MOOs	B-Application
as	O
a	O
medium	O
.	O
</s>
<s>
BioMOO	O
Wizards	B-Application
created	O
a	O
portable	O
subset	O
of	O
the	O
BioMOO	O
server	O
,	O
called	O
the	O
Virtual	O
Conference	O
Center	O
,	O
and	O
submitted	O
it	O
as	O
a	O
paper	O
at	O
a	O
virtual	O
scientific	O
conference	O
and	O
used	O
the	O
VCC	O
to	O
host	O
another	O
virtual	O
scientific	O
conference	O
.	O
</s>
<s>
Prilusky	O
and	O
Glusman	O
also	O
released	O
in	O
1994	O
the	O
File	O
Utilities	O
Package	O
,	O
a	O
MOO	B-Application
server	O
modification	O
enabling	O
direct	O
but	O
controlled	O
access	O
to	O
the	O
underlying	O
file	O
system	O
.	O
</s>
<s>
LinguaMOO	O
is	O
an	O
educational	O
MOO	B-Application
dedicated	O
to	O
general	O
studies	O
of	O
arts	O
and	O
humanities	O
,	O
created	O
in	O
1995	O
by	O
Cynthia	O
Haynes	O
of	O
the	O
University	O
of	O
Texas	O
at	O
Dallas	O
and	O
Jan	O
Rune	O
Holmevik	O
of	O
the	O
University	O
of	O
Bergen	O
.	O
</s>
<s>
Many	O
educational	O
MOOs	B-Application
use	O
the	O
enCore	O
system	O
,	O
derived	O
from	O
LinguaMOO	O
,	O
for	O
their	O
MOO	B-Application
database	O
core	O
.	O
</s>
<s>
Haynes	O
and	O
Holmevik	O
published	O
two	O
books	O
on	O
the	O
educational	O
use	O
of	O
MOOs	B-Application
.	O
</s>
<s>
It	O
was	O
the	O
first	O
MOO	B-Application
in	O
Spanish	O
,	O
complete	O
with	O
Spanish	O
commands	O
and	O
accents	O
,	O
built	O
for	O
native	O
speakers	O
,	O
learners	O
and	O
teachers	O
of	O
Spanish	O
.	O
</s>
<s>
ATHEMOO	B-Protocol
started	O
in	O
1995	O
at	O
the	O
University	O
of	O
Hawaii	O
and	O
was	O
an	O
online	O
performance	O
and	O
teaching	O
space	O
for	O
academics	O
and	O
professionals	O
with	O
an	O
interest	O
in	O
theatre	O
.	O
</s>
<s>
At	O
its	O
height	O
2200	O
people	O
were	O
involved	O
in	O
ATHE	O
and	O
ATHEMOO	B-Protocol
.	O
</s>
<s>
HellMOO	O
is	O
a	O
now-defunct	O
role-playing	O
MOO	B-Application
that	O
had	O
been	O
online	O
since	O
2004	O
.	O
</s>
